diff --git a/Gemfile b/Gemfile
index 17b564d1f..db9ecace8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -48,7 +48,7 @@ gem 'bootsnap', require: false
 # gem "sassc-rails"
 
 # Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
-# gem "image_processing", "~> 1.2"
+gem 'image_processing', '~> 1.2'
 
 group :development, :test do
   # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
diff --git a/Gemfile.lock b/Gemfile.lock
index 4d1570331..9469d0be7 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -321,6 +321,7 @@ DEPENDENCIES
   erb_lint
   faker
   i18n_generators
+  image_processing (~> 1.2)
   importmap-rails
   jbuilder
   kaminari
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index aeb7d7079..67b56c09e 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -7,7 +7,7 @@ class ApplicationController < ActionController::Base
   protected
 
   def configure_permitted_parameters
-    keys = %i[name postal_code address self_introduction]
+    keys = %i[name postal_code address self_introduction avatar]
     devise_parameter_sanitizer.permit(:sign_up, keys:)
     devise_parameter_sanitizer.permit(:account_update, keys:)
   end
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 35c5d1a1d..d7eab1743 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -2,7 +2,7 @@
 
 class UsersController < ApplicationController
   def index
-    @users = User.order(:id).page(params[:page])
+    @users = User.with_attached_avatar.order(:id).page(params[:page])
   end
 
   def show
diff --git a/app/models/user.rb b/app/models/user.rb
index 3c292a1a5..be3d3d72a 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -3,4 +3,8 @@
 class User < ApplicationRecord
   devise :database_authenticatable, :registerable,
          :recoverable, :rememberable, :validatable
+
+  has_one_attached :avatar do |attachable|
+    attachable.variant :thumb, resize_to_limit: [150, 150]
+  end
 end
diff --git a/app/views/devise/registrations/_profile_fields.html.erb b/app/views/devise/registrations/_profile_fields.html.erb
index 0299b9fdd..79f2a7a8f 100644
--- a/app/views/devise/registrations/_profile_fields.html.erb
+++ b/app/views/devise/registrations/_profile_fields.html.erb
@@ -17,3 +17,8 @@
   <%= f.label :self_introduction %><br />
   <%= f.text_area :self_introduction %>
 </div>
+
+<div class="field">
+  <%= f.label :avatar %><br />
+  <%= f.file_field :avatar, autocomplete: "avatar" %>
+</div>
diff --git a/app/views/users/_user.html.erb b/app/views/users/_user.html.erb
index 015220da8..c42e55e0d 100644
--- a/app/views/users/_user.html.erb
+++ b/app/views/users/_user.html.erb
@@ -25,4 +25,12 @@
     <%= user.self_introduction %>
   </p>
 
+  <p>
+    <strong><%= User.human_attribute_name(:avatar) %>:</strong>
+    <% if user.avatar.attached? %>
+      <br>
+      <%= image_tag user.avatar.variant(:thumb) %>
+    <% end %>
+  </p>
+
 </div>
diff --git a/config/locales/translation_ja.yml b/config/locales/translation_ja.yml
index 64a08065e..bfb0b0601 100644
--- a/config/locales/translation_ja.yml
+++ b/config/locales/translation_ja.yml
@@ -15,3 +15,4 @@ ja:
         postal_code: 郵便番号
         address: 住所
         self_introduction: 自己紹介文
+        avatar: ユーザ画像
diff --git a/db/migrate/20230102070626_create_active_storage_tables.active_storage.rb b/db/migrate/20230102070626_create_active_storage_tables.active_storage.rb
new file mode 100644
index 000000000..8a7bfe189
--- /dev/null
+++ b/db/migrate/20230102070626_create_active_storage_tables.active_storage.rb
@@ -0,0 +1,57 @@
+# This migration comes from active_storage (originally 20170806125915)
+class CreateActiveStorageTables < ActiveRecord::Migration[5.2]
+  def change
+    # Use Active Record's configured type for primary and foreign keys
+    primary_key_type, foreign_key_type = primary_and_foreign_key_types
+
+    create_table :active_storage_blobs, id: primary_key_type do |t|
+      t.string   :key,          null: false
+      t.string   :filename,     null: false
+      t.string   :content_type
+      t.text     :metadata
+      t.string   :service_name, null: false
+      t.bigint   :byte_size,    null: false
+      t.string   :checksum
+
+      if connection.supports_datetime_with_precision?
+        t.datetime :created_at, precision: 6, null: false
+      else
+        t.datetime :created_at, null: false
+      end
+
+      t.index [ :key ], unique: true
+    end
+
+    create_table :active_storage_attachments, id: primary_key_type do |t|
+      t.string     :name,     null: false
+      t.references :record,   null: false, polymorphic: true, index: false, type: foreign_key_type
+      t.references :blob,     null: false, type: foreign_key_type
+
+      if connection.supports_datetime_with_precision?
+        t.datetime :created_at, precision: 6, null: false
+      else
+        t.datetime :created_at, null: false
+      end
+
+      t.index [ :record_type, :record_id, :name, :blob_id ], name: :index_active_storage_attachments_uniqueness, unique: true
+      t.foreign_key :active_storage_blobs, column: :blob_id
+    end
+
+    create_table :active_storage_variant_records, id: primary_key_type do |t|
+      t.belongs_to :blob, null: false, index: false, type: foreign_key_type
+      t.string :variation_digest, null: false
+
+      t.index [ :blob_id, :variation_digest ], name: :index_active_storage_variant_records_uniqueness, unique: true
+      t.foreign_key :active_storage_blobs, column: :blob_id
+    end
+  end
+
+  private
+    def primary_and_foreign_key_types
+      config = Rails.configuration.generators
+      setting = config.options[config.orm][:primary_key_type]
+      primary_key_type = setting || :primary_key
+      foreign_key_type = setting || :bigint
+      [primary_key_type, foreign_key_type]
+    end
+end
diff --git a/db/schema.rb b/db/schema.rb
index eff7e9fb7..325f42495 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,35 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2023_01_02_023317) do
+ActiveRecord::Schema[7.0].define(version: 2023_01_02_070626) do
+  create_table "active_storage_attachments", force: :cascade do |t|
+    t.string "name", null: false
+    t.string "record_type", null: false
+    t.bigint "record_id", null: false
+    t.bigint "blob_id", null: false
+    t.datetime "created_at", null: false
+    t.index ["blob_id"], name: "index_active_storage_attachments_on_blob_id"
+    t.index ["record_type", "record_id", "name", "blob_id"], name: "index_active_storage_attachments_uniqueness", unique: true
+  end
+
+  create_table "active_storage_blobs", force: :cascade do |t|
+    t.string "key", null: false
+    t.string "filename", null: false
+    t.string "content_type"
+    t.text "metadata"
+    t.string "service_name", null: false
+    t.bigint "byte_size", null: false
+    t.string "checksum"
+    t.datetime "created_at", null: false
+    t.index ["key"], name: "index_active_storage_blobs_on_key", unique: true
+  end
+
+  create_table "active_storage_variant_records", force: :cascade do |t|
+    t.bigint "blob_id", null: false
+    t.string "variation_digest", null: false
+    t.index ["blob_id", "variation_digest"], name: "index_active_storage_variant_records_uniqueness", unique: true
+  end
+
   create_table "books", force: :cascade do |t|
     t.string "title"
     t.text "memo"
@@ -36,4 +64,6 @@
     t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
   end
 
+  add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
+  add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
 end
diff --git a/db/seeds.rb b/db/seeds.rb
index c80a48e30..ebab5cef3 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -1,5 +1,9 @@
 # frozen_string_literal: true
 
+# queue_adapterを変更している理由とtransactionを使っている理由は下記URLを参照
+# https://bootcamp.fjord.jp/questions/779#answer_2262
+ActiveStorage::AnalyzeJob.queue_adapter = :inline
+
 print '開発環境のデータをすべて削除して初期データを投入します。よろしいですか？[Y/n]: ' # rubocop:disable Rails/Output
 unless $stdin.gets.chomp.casecmp('Y').zero?
   puts '中止しました。' # rubocop:disable Rails/Output
@@ -10,50 +14,65 @@ def picture_file(name)
   File.open(Rails.root.join("db/seeds/#{name}"))
 end
 
+puts '実行中です。しばらくお待ちください...' # rubocop:disable Rails/Output
+
 Book.destroy_all
 
-Book.create!(
-  title: 'Ruby超入門',
-  memo: 'Rubyの文法の基本をやさしくていねいに解説しています。',
-  author: '五十嵐 邦明',
-  picture: picture_file('cho-nyumon.jpg')
-)
-
-Book.create!(
-  title: 'チェリー本',
-  memo: 'プログラミング経験者のためのRuby入門書です。',
-  author: '伊藤 淳一',
-  picture: picture_file('cherry-book.jpg')
-)
-
-Book.create!(
-  title: '楽々ERDレッスン',
-  memo: '実在する帳票から本当に使えるテーブル設計を導く画期的な本！',
-  author: '羽生 章洋',
-  picture: picture_file('erd.jpg')
-)
-
-50.times do
+Book.transaction do # rubocop:disable Metrics/BlockLength
   Book.create!(
-    title: Faker::Book.title,
-    memo: Faker::Book.genre,
-    author: Faker::Book.author,
-    picture: picture_file('no-image.png')
+    title: 'Ruby超入門',
+    memo: 'Rubyの文法の基本をやさしくていねいに解説しています。',
+    author: '五十嵐 邦明',
+    picture: picture_file('cho-nyumon.jpg')
   )
+
+  Book.create!(
+    title: 'チェリー本',
+    memo: 'プログラミング経験者のためのRuby入門書です。',
+    author: '伊藤 淳一',
+    picture: picture_file('cherry-book.jpg')
+  )
+
+  Book.create!(
+    title: '楽々ERDレッスン',
+    memo: '実在する帳票から本当に使えるテーブル設計を導く画期的な本！',
+    author: '羽生 章洋',
+    picture: picture_file('erd.jpg')
+  )
+
+  50.times do
+    Book.create!(
+      title: Faker::Book.title,
+      memo: Faker::Book.genre,
+      author: Faker::Book.author,
+      picture: picture_file('no-image.png')
+    )
+  end
 end
 
 User.destroy_all
 
-50.times do |n|
-  name = Faker::Name.name
-  User.create!(
-    email: "sample-#{n}@example.com",
-    password: 'password',
-    name:,
-    postal_code: "123-#{n.to_s.rjust(4, '0')}",
-    address: Faker::Address.full_address,
-    self_introduction: "こんにちは、#{name}です。"
-  )
+User.transaction do
+  50.times do |n|
+    name = Faker::Name.name
+    User.create!(
+      email: "sample-#{n}@example.com",
+      password: 'password',
+      name:,
+      postal_code: "123-#{n.to_s.rjust(4, '0')}",
+      address: Faker::Address.full_address,
+      self_introduction: "こんにちは、#{name}です。"
+    )
+  end
+end
+
+# 画像は読み込みに時間がかかるので一部のデータだけにする
+User.order(:id).each.with_index(1) do |user, n|
+  next unless (n % 8).zero?
+
+  number = rand(1..6)
+  image_path = Rails.root.join("db/seeds/avatar-#{number}.png")
+  user.avatar.attach(io: File.open(image_path), filename: 'avatar.png')
 end
 
 puts '初期データの投入が完了しました。' # rubocop:disable Rails/Output
diff --git a/db/seeds/avatar-1.png b/db/seeds/avatar-1.png
new file mode 100644
index 000000000..0686801dc
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diff --git a/db/seeds/avatar-3.png b/db/seeds/avatar-3.png
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diff --git a/db/seeds/avatar-4.png b/db/seeds/avatar-4.png
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diff --git a/db/seeds/avatar-5.png b/db/seeds/avatar-5.png
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diff --git a/db/seeds/avatar-6.png b/db/seeds/avatar-6.png
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