diff --git a/07.ls_object/bin/ls.rb b/07.ls_object/bin/ls.rb
new file mode 100755
index 0000000000..87e7cc6fa2
--- /dev/null
+++ b/07.ls_object/bin/ls.rb
@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require 'io/console'
+require 'optparse'
+require_relative '../lib/ls_command'
+
+if __FILE__ == $PROGRAM_NAME
+  opt = OptionParser.new
+
+  params = { dot_match: false }
+  opt.on('-a') { |v| params[:dot_match] = v }
+  opt.on('-r') { |v| params[:reverse] = v }
+  opt.on('-l') { |v| params[:long_format] = v }
+  opt.parse!(ARGV)
+  path = ARGV[0] || '.'
+  width = IO.console.winsize[1]
+
+  ls = LsCommand.new(path, width:, **params)
+  puts ls.formatted_output
+end
diff --git a/07.ls_object/lib/file/file_data.rb b/07.ls_object/lib/file/file_data.rb
new file mode 100755
index 0000000000..851757fdd9
--- /dev/null
+++ b/07.ls_object/lib/file/file_data.rb
@@ -0,0 +1,82 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require 'etc'
+require 'pathname'
+
+class FileData
+  attr_reader :name, :file_status
+
+  PERMISSION_START_POSITION = 7
+  PERMISSION_END_POSITION = 9
+
+  FILE_TYPE = {
+    'fifo' => 'p',
+    'characterSpecial' => 'c',
+    'directory' => 'd',
+    'blockSpecial' => 'b',
+    'file' => '-',
+    'link' => 'l',
+    'socket' => 's'
+  }.freeze
+
+  SPECIAL_PERMISSION = {
+    0 => 's',
+    1 => 's',
+    2 => 't'
+  }.freeze
+
+  PERMISSION_TYPE = {
+    '000' => '---',
+    '001' => '--x',
+    '010' => '-w-',
+    '011' => '-wx',
+    '100' => 'r--',
+    '101' => 'r-x',
+    '110' => 'rw-',
+    '111' => 'rwx'
+  }.freeze
+
+  def initialize(name, path)
+    @name = name
+    @full_path = Pathname(File.absolute_path(@name, path))
+    @file_type = File.ftype(@full_path)
+    @file_status = build_file_status(File.lstat(@full_path))
+  end
+
+  private
+
+  def build_file_status(status)
+    {
+      type: FILE_TYPE[status.ftype],
+      mode: mode(status),
+      hardlink_nums: status.nlink.to_s,
+      owner_name: Etc.getpwuid(status.uid).name,
+      group_name: Etc.getgrgid(status.gid).name,
+      bytesize: rdev_or_bytesize(status),
+      latest_modify_datetime: status.mtime.strftime('%_m %e %H:%M'),
+      filename: file_name(status),
+      blocks: status.blocks
+    }
+  end
+
+  def file_name(status)
+    status.symlink? ? "#{@name} -> #{File.readlink(@full_path)}" : @name
+  end
+
+  def mode(status)
+    mode_binary_numbers = status.mode.to_s(2).rjust(16, '0')
+    # SUID、SGID、STICKEYBITの順番で特殊権限をチェック
+    mode_binary_numbers[4..6].each_char.with_index.map do |special_permission, i|
+      range_start = PERMISSION_START_POSITION + (3 * i)
+      range_end = PERMISSION_END_POSITION + (3 * i)
+      permission = PERMISSION_TYPE[mode_binary_numbers[range_start..range_end]].dup
+      permission[2] = permission[2] == 'x' ? SPECIAL_PERMISSION[i] : SPECIAL_PERMISSION[i].upcase if special_permission == '1'
+      permission
+    end.join
+  end
+
+  def rdev_or_bytesize(status)
+    %w[characterSpecial blockSpecial].include?(@file_type) ? format('%#01x', status.rdev.to_s(10)) : status.size.to_s
+  end
+end
diff --git a/07.ls_object/lib/format/formatter.rb b/07.ls_object/lib/format/formatter.rb
new file mode 100644
index 0000000000..9a2579f38c
--- /dev/null
+++ b/07.ls_object/lib/format/formatter.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Formatter
+  def initialize(files)
+    @files = files
+  end
+
+  def format; end
+end
diff --git a/07.ls_object/lib/format/long_formatter.rb b/07.ls_object/lib/format/long_formatter.rb
new file mode 100644
index 0000000000..3a0d1b9ffe
--- /dev/null
+++ b/07.ls_object/lib/format/long_formatter.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require_relative 'formatter'
+
+class LongFormatter < Formatter
+  def initialize(files, path)
+    super(files)
+    @path = path
+    @max_sizes = build_max_sizes
+    @total_block = sum_blocks
+    @long_format_data = build_long_format_data
+  end
+
+  def format
+    total = "total #{@total_block}" if File.directory?(@path) || @files.size > 1
+    [total, *@long_format_data].compact.join("\n")
+  end
+
+  private
+
+  def build_long_format_data
+    @files.map { |file| format_row(file.file_status, *@max_sizes) }
+  end
+
+  def build_max_sizes
+    %i[hardlink_nums owner_name group_name bytesize].map do |key|
+      find_max_size(key)
+    end
+  end
+
+  def find_max_size(key)
+    @files.map { |file| file.file_status[key].size }.max
+  end
+
+  def format_row(status, max_nlink, max_user, max_group, max_size)
+    [
+      "#{status[:type]}#{status[:mode]}",
+      "  #{status[:hardlink_nums].rjust(max_nlink)}",
+      " #{status[:owner_name].ljust(max_user)}",
+      "  #{status[:group_name].ljust(max_group)}",
+      "  #{status[:bytesize].rjust(max_size)}",
+      " #{status[:latest_modify_datetime]}",
+      " #{status[:filename]}"
+    ].join
+  end
+
+  def sum_blocks
+    @files.sum { |file| file.file_status[:blocks] }
+  end
+end
diff --git a/07.ls_object/lib/format/short_formatter.rb b/07.ls_object/lib/format/short_formatter.rb
new file mode 100644
index 0000000000..2119ac87aa
--- /dev/null
+++ b/07.ls_object/lib/format/short_formatter.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require_relative 'formatter'
+
+class ShortFormatter < Formatter
+  def initialize(files, width)
+    super(files)
+    @width = width
+    @max_file_name = @files.map { |file| File.basename(file.name).size }.max
+    @col_count = calculate_col_count
+    @row_count = calculate_row_count
+    @short_format_data = build_short_format_data
+  end
+
+  def format
+    @short_format_data.join("\n")
+  end
+
+  private
+
+  def build_short_format_data
+    safe_transpose.map { |row_files| build_short_format_row(row_files) }
+  end
+
+  def build_short_format_row(row_files)
+    row_files.map do |file|
+      basename = file ? File.basename(file.name) : ''
+      basename.ljust(@max_file_name + 1)
+    end.join.rstrip
+  end
+
+  def calculate_col_count
+    @width / (@max_file_name + 1)
+  end
+
+  def calculate_row_count
+    @col_count.zero? ? @files.count : (@files.count.to_f / @col_count).ceil
+  end
+
+  def safe_transpose
+    nested_file_names = @files.each_slice(@row_count).to_a
+    nested_file_names[0].zip(*nested_file_names[1..])
+  end
+end
diff --git a/07.ls_object/lib/ls_command.rb b/07.ls_object/lib/ls_command.rb
new file mode 100644
index 0000000000..6ad6e0940e
--- /dev/null
+++ b/07.ls_object/lib/ls_command.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require_relative 'file/file_data'
+require_relative 'format/long_formatter'
+require_relative 'format/short_formatter'
+
+class LsCommand
+  def initialize(path, width: 80, dot_match: false, reverse: false, long_format: false)
+    @path = path
+    @width = width
+    @dot_match = dot_match
+    @reverse = reverse
+    @long_format = long_format
+    @files = build_dot_match_and_sorted_files
+  end
+
+  def formatted_output
+    @long_format ? LongFormatter.new(@files, @path).format : ShortFormatter.new(@files, @width).format
+  end
+
+  private
+
+  def build_dot_match_and_sorted_files
+    files = generate_files
+    matched_files = @dot_match ? files : files.filter { |file| !/^\./.match?(file.name) }
+    @reverse ? matched_files.sort_by(&:name).reverse : matched_files.sort_by(&:name)
+  end
+
+  def generate_files
+    if File.directory?(@path)
+      Dir.open(@path).entries.map { |name| FileData.new(name, @path) }
+    else
+      [FileData.new(@path, File.dirname(@path))]
+    end
+  end
+end
diff --git a/07.ls_object/test/ls_command_test.rb b/07.ls_object/test/ls_command_test.rb
new file mode 100644
index 0000000000..1d4033f054
--- /dev/null
+++ b/07.ls_object/test/ls_command_test.rb
@@ -0,0 +1,191 @@
+# frozen_string_literal: true
+
+require_relative 'test_helper'
+require_relative '../lib/ls_command'
+
+class LsCommandTest < Minitest::Test
+  def test_display_a_file
+    ls_command = LsCommand.new('test/test_dir/test_one_file')
+    assert_equal 'test.txt', ls_command.formatted_output
+  end
+
+  def test_display_files
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files')
+    assert_equal 'dir        test.txt   test_2.txt', ls_command.formatted_output
+  end
+
+  def test_display_match_dot_files
+    params = { dot_match: true }
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files', **params)
+    assert_equal '.          ..         .test      dir        test.txt   test_2.txt', ls_command.formatted_output
+  end
+
+  def test_display_reverse_sort_files
+    params = { reverse: true, dot_match: false }
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files', **params)
+    assert_equal 'test_2.txt test.txt   dir', ls_command.formatted_output
+  end
+
+  def test_display_dot_match_and_reverse_sort_file
+    params = { reverse: true, dot_match: true }
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files', **params)
+    assert_equal 'test_2.txt test.txt   dir        .test      ..         .', ls_command.formatted_output
+  end
+
+  def test_display_long_format_file
+    # Output example
+    #  total 8
+    #  -rw-r--r--  1 username  staff  10  9 15 14:34 test.txt
+    path = 'test/test_dir/test_one_file'
+    params = { long_format: true }
+    expected = `ls -l #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_long_format_and_dot_match_file
+    # Output example
+    # total 16
+    # drwxr-xr-x  6 username  staff  192  9 16 15:18 .
+    # drwxr-xr-x  5 username  staff  160  9 19 18:20 ..
+    # -rw-r--r--  1 username  staff    0  9 16 15:14 .test
+    # drwxr-xr-x  2 username  staff   64  9 16 15:18 dir
+    # -rw-r--r--  1 username  staff   10  9 16 15:14 test.txt
+    # -rw-r--r--  1 username  staff   10  9 16 15:14 test_2.txt
+    path = 'test/test_dir/test_include_dir_and_dot_files'
+    params = { long_format: true, dot_match: true }
+    expected = `ls -al #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_long_format_and_dot_match_and_reverse_file
+    # Output example
+    # total 16
+    #  -rw-r--r--  1 username  staff   10  9 16 15:14 test_2.txt
+    #  -rw-r--r--  1 username  staff   10  9 16 15:14 test.txt
+    #  drwxr-xr-x  2 username  staff   64  9 16 15:18 dir
+    #  -rw-r--r--  1 username  staff    0  9 16 15:14 .test
+    #  drwxr-xr-x  5 username  staff  160  9 19 18:20 ..
+    #  drwxr-xr-x  6 username  staff  192  9 16 15:18 .
+    params = { reverse: true, long_format: true, dot_match: true }
+    path = 'test/test_dir/test_include_dir_and_dot_files'
+    expected = `ls -arl #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_width_eighty
+    params = { dot_match: true }
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files', **params)
+    assert_equal '.          ..         .test      dir        test.txt   test_2.txt', ls_command.formatted_output
+  end
+
+  def test_display_width_fourty
+    params = { dot_match: true }
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files', width: 40, **params)
+    expected = <<~LS_RESULT.chomp
+      .          .test      test.txt
+      ..         dir        test_2.txt
+    LS_RESULT
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_width_thirty
+    params = { dot_match: true }
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files', width: 30, **params)
+    expected = <<~LS_RESULT.chomp
+      .          dir
+      ..         test.txt
+      .test      test_2.txt
+    LS_RESULT
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_width_twenty
+    params = { dot_match: true }
+    ls_command = LsCommand.new('test/test_dir/test_include_dir_and_dot_files', width: 20, **params)
+    expected = <<~LS_RESULT.chomp
+      .
+      ..
+      .test
+      dir
+      test.txt
+      test_2.txt
+    LS_RESULT
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_special_permission
+    # Output example
+    # total 0
+    # -rwxr-sr-x  1 username  staff  0 10  7 21:46 set_group_id_file.txt
+    # -rwxr-Sr-x  1 username  staff  0 10  7 22:05 set_group_id_file_not_x_permission.txt
+    # -r-Sr-Sr-T  1 username  staff  0 10 17 00:18 set_user_id_and_group_id_and_sticky_bit_permission.txt
+    # -rwsr-sr-x  1 username  staff  0 10 17 00:17 set_user_id_and_group_id_permission.txt
+    # -rwsr-xr-x  1 username  staff  0 10  7 21:46 set_user_id_file.txt
+    # -r-Sr-xr-x  1 username  staff  0 10  7 22:05 set_user_id_file_not_x_permission.txt
+    # -rwxr-xr-t  1 username  staff  0 10  7 21:46 sticky_bit_file.txt
+    # -rwxr-xr-T  1 username  staff  0 10  7 21:51 sticky_bit_file_not_x_permission.txt
+    params = { long_format: true }
+    path = 'test/test_dir/special_permission_dir'
+    `chmod 2755 #{path}/set_group_id_file.txt` # group permissionに実行権限xと特殊権限を付与
+    `chmod 2745 #{path}/set_group_id_file_not_x_permission.txt` # group permissionの実行権限xを外し特殊権限を付与
+    `chmod 4755 #{path}/set_user_id_file.txt` # owner permissionに実行権限xと特殊権限を付与
+    `chmod 4455 #{path}/set_user_id_file_not_x_permission.txt` # owner permissionの実行権限xを外し特殊権限を付与
+    `chmod 1755 #{path}/sticky_bit_file.txt` # other permissionに実行権限xと特殊権限を付与
+    `chmod 1754 #{path}/sticky_bit_file_not_x_permission.txt` # other permissionの実行権限xを外し特殊権限を付与
+    `chmod 6755 test/test_dir/special_permission_dir/set_user_id_and_group_id_permission.txt`
+    `chmod 7444 test/test_dir/special_permission_dir/set_user_id_and_group_id_and_sticky_bit_permission.txt`
+    expected = `ls -l #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_some_file_types
+    # Output example
+    # total 0
+    # drwxr-xr-x  2 username  staff   64 10  7 23:12 test_dir
+    # -rw-r--r--  1 username  staff    0 10  7 23:07 test_file.txt
+    # lrwxr-xr-x  1 username  staff  102 10  7 22:59 test_link -> ../07.ls_object/test/test_dir/link_dir/link_test.txt # フルパスのため省略
+    # prw-r--r--  1 username  staff    0 10  8 01:17 testfile
+    params = { long_format: true }
+    path = 'test/test_dir/file_type_dir'
+    # パイプファイルの作成
+    `mkfifo test/test_dir/file_type_dir/test_fifo_file` unless File.exist?('test/test_dir/file_type_dir/test_fifo_file')
+    expected = `ls -l #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_block_device_file_type
+    # Output example
+    # brw-r-----  1 root  operator  0x1000004  9  8 09:43 /dev/disk1
+    params = { long_format: true }
+    path = '/dev/disk1'
+    expected = `ls -l #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_character_device_file_file_type
+    # Output example
+    # total 0
+    # crw-rw-rw-  1 root  wheel  0x3000002 10  8 01:26 /dev/null
+    params = { long_format: true }
+    path = '/dev/null'
+    expected = `ls -l #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+
+  def test_display_local_domain_sockets_file_type
+    # Output example
+    # srw-------  1 root  daemon  0  9  8 09:43 /var/run/vpncontrol.sock
+    params = { long_format: true }
+    path = '/var/run/vpncontrol.sock'
+    expected = `ls -l #{path}`.chomp
+    ls_command = LsCommand.new(path, **params)
+    assert_equal expected, ls_command.formatted_output
+  end
+end
diff --git a/07.ls_object/test/test_dir/file_type_dir/link_test b/07.ls_object/test/test_dir/file_type_dir/link_test
new file mode 120000
index 0000000000..4fb2b3f711
--- /dev/null
+++ b/07.ls_object/test/test_dir/file_type_dir/link_test
@@ -0,0 +1 @@
+/test/test_dir/link_dir/link_test.txt
\ No newline at end of file
diff --git a/07.ls_object/test/test_dir/file_type_dir/test_file.txt b/07.ls_object/test/test_dir/file_type_dir/test_file.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/link_dir/link_test.txt b/07.ls_object/test/test_dir/link_dir/link_test.txt
new file mode 100644
index 0000000000..4b0a21d6fc
--- /dev/null
+++ b/07.ls_object/test/test_dir/link_dir/link_test.txt
@@ -0,0 +1 @@
+testtest
\ No newline at end of file
diff --git a/07.ls_object/test/test_dir/special_permission_dir/set_group_id_file.txt b/07.ls_object/test/test_dir/special_permission_dir/set_group_id_file.txt
new file mode 100755
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/special_permission_dir/set_group_id_file_not_x_permission.txt b/07.ls_object/test/test_dir/special_permission_dir/set_group_id_file_not_x_permission.txt
new file mode 100755
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/special_permission_dir/set_user_id_and_group_id_and_sticky_bit_permission.txt b/07.ls_object/test/test_dir/special_permission_dir/set_user_id_and_group_id_and_sticky_bit_permission.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/special_permission_dir/set_user_id_and_group_id_permission.txt b/07.ls_object/test/test_dir/special_permission_dir/set_user_id_and_group_id_permission.txt
new file mode 100755
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/special_permission_dir/set_user_id_file.txt b/07.ls_object/test/test_dir/special_permission_dir/set_user_id_file.txt
new file mode 100755
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/special_permission_dir/set_user_id_file_not_x_permission.txt b/07.ls_object/test/test_dir/special_permission_dir/set_user_id_file_not_x_permission.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/special_permission_dir/sticky_bit_file.txt b/07.ls_object/test/test_dir/special_permission_dir/sticky_bit_file.txt
new file mode 100755
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/special_permission_dir/sticky_bit_file_not_x_permission.txt b/07.ls_object/test/test_dir/special_permission_dir/sticky_bit_file_not_x_permission.txt
new file mode 100755
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/test_include_dir_and_dot_files/.test b/07.ls_object/test/test_dir/test_include_dir_and_dot_files/.test
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/07.ls_object/test/test_dir/test_include_dir_and_dot_files/test.txt b/07.ls_object/test/test_dir/test_include_dir_and_dot_files/test.txt
new file mode 100644
index 0000000000..910898e128
--- /dev/null
+++ b/07.ls_object/test/test_dir/test_include_dir_and_dot_files/test.txt
@@ -0,0 +1 @@
+testです
\ No newline at end of file
diff --git a/07.ls_object/test/test_dir/test_include_dir_and_dot_files/test_2.txt b/07.ls_object/test/test_dir/test_include_dir_and_dot_files/test_2.txt
new file mode 100644
index 0000000000..910898e128
--- /dev/null
+++ b/07.ls_object/test/test_dir/test_include_dir_and_dot_files/test_2.txt
@@ -0,0 +1 @@
+testです
\ No newline at end of file
diff --git a/07.ls_object/test/test_dir/test_one_file/test.txt b/07.ls_object/test/test_dir/test_one_file/test.txt
new file mode 100644
index 0000000000..910898e128
--- /dev/null
+++ b/07.ls_object/test/test_dir/test_one_file/test.txt
@@ -0,0 +1 @@
+testです
\ No newline at end of file
diff --git a/07.ls_object/test/test_helper.rb b/07.ls_object/test/test_helper.rb
new file mode 100644
index 0000000000..90d46e9bc6
--- /dev/null
+++ b/07.ls_object/test/test_helper.rb
@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+require 'minitest/autorun'
+require 'minitest/pride'