diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 00000000..b10f351d
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,51 @@
+# inherit_from: .rubocop_todo.yml
+
+require:
+  - rubocop-rails
+
+AllCops:
+  NewCops: enable
+  DisplayCopNames: true
+  Exclude:
+  - 'vendor/**/*'
+  - 'node_modules/**/*'
+  - 'spec/**/*'
+  - 'db/schema.rb'
+  - 'db/**/*'
+  - 'config/**/*'
+  - 'Guardfile'
+  - 'bin/**/*'
+  - 'tmp/**/*'
+
+Style/Documentation:
+  Enabled: false
+
+Style/FrozenStringLiteralComment:
+  Enabled: false
+
+Style/StringLiterals:
+  EnforcedStyle: single_quotes
+
+Style/StringLiteralsInInterpolation:
+  EnforcedStyle: single_quotes
+
+Style/TrailingCommaInArrayLiteral:
+  EnforcedStyleForMultiline: comma
+
+Metrics/BlockLength:
+  Max: 52
+
+Metrics/ClassLength:
+  Max: 500
+
+Metrics/CyclomaticComplexity:
+  Max: 16
+
+Metrics/MethodLength:
+  Max: 65
+
+Metrics/PerceivedComplexity:
+  Max: 17
+
+Metrics/ModuleLength:
+  Max: 160
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 32faeb5a..7cd3ede8 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class ApplicationController < ActionController::Base
-  if Rails.env == 'YOUR_ENVIRONMENT'
+  if Rails.env.YOUR_ENVIRONMENT?
     USERNAME = Rails.application.credentials.digest_auth[:username].freeze
     PASSWORD = Rails.application.credentials.digest_auth[:password].freeze
 
diff --git a/app/lib/operate_spreadsheet.rb b/app/lib/operate_spreadsheet.rb
index d9148812..795b2b41 100644
--- a/app/lib/operate_spreadsheet.rb
+++ b/app/lib/operate_spreadsheet.rb
@@ -7,7 +7,7 @@ def self.session
       client_secret: Rails.application.credentials.spreadsheet_api[:client_secret],
       scope: [
         'https://www.googleapis.com/auth/drive',
-        'https://spreadsheets.google.com/feeds/'
+        'https://spreadsheets.google.com/feeds/',
       ],
       refresh_token: Rails.application.credentials.spreadsheet_api[:refresh_token]
     )
@@ -31,7 +31,7 @@ def self.master_data
       is_retweet: 0
     }
     tweeted_at_validation = {
-      tweeted_at: '2018-06-22 21:00:00'.in_time_zone('Tokyo')..'2018-06-24 09:59:59'.in_time_zone('Tokyo')
+      tweeted_at: ('2018-06-22 21:00:00'.in_time_zone('Tokyo'))..('2018-06-24 09:59:59'.in_time_zone('Tokyo'))
     }
     user_id_validation = {
       user_id: 28
@@ -72,7 +72,7 @@ def self.divided_sheets
     tweeted_at_index        = 18 # R列
 
     # TODO: whereの条件を分割する
-    tweets_ascending = Tweet.where(is_retweet: 0).where(tweeted_at: '2018-06-22 21:00:00'.in_time_zone('Tokyo')..'2018-06-24 09:00:00'.in_time_zone('Tokyo')).where.not(user_id: 28).order(tweeted_at: :asc)
+    tweets_ascending = Tweet.where(is_retweet: 0).where(tweeted_at: ('2018-06-22 21:00:00'.in_time_zone('Tokyo'))..('2018-06-24 09:00:00'.in_time_zone('Tokyo'))).where.not(user_id: 28).order(tweeted_at: :asc)
 
     # TODO: NOT DRY
     target_worksheets = [
@@ -95,7 +95,7 @@ def self.divided_sheets
       'ツイ 17',
       'ツイ 18',
       'ツイ 19',
-      'ツイ 20'
+      'ツイ 20',
     ]
 
     # 100 ごとに分割
diff --git a/app/lib/twitter_api/search_tweet.rb b/app/lib/twitter_api/search_tweet.rb
index 7df0a927..2b4d4104 100644
--- a/app/lib/twitter_api/search_tweet.rb
+++ b/app/lib/twitter_api/search_tweet.rb
@@ -20,10 +20,8 @@ def self.search_word_tweet_exists?(search_word:)
       # TODO: 汚い
       if SearchWord.where(word: search_word).first.nil?
         false
-      elsif SearchWord.where(word: search_word).first.tweets.empty?
-        false
       else
-        true
+        !SearchWord.where(word: search_word).first.tweets.empty?
       end
     end
 
diff --git a/app/lib/twitter_api/upsert_objects/search_words_table.rb b/app/lib/twitter_api/upsert_objects/search_words_table.rb
index 1813ef16..e7e0b237 100644
--- a/app/lib/twitter_api/upsert_objects/search_words_table.rb
+++ b/app/lib/twitter_api/upsert_objects/search_words_table.rb
@@ -11,8 +11,8 @@ def self.upsert(search_word:)
                 word: search_word
               },
               {
-                created_at: Time.now,
-                updated_at: Time.now
+                created_at: Time.zone.now,
+                updated_at: Time.zone.now
               }
             )
           end
diff --git a/app/lib/twitter_api/upserted_columns_hash/tweet_hash.rb b/app/lib/twitter_api/upserted_columns_hash/tweet_hash.rb
index 67262c2f..67a0e623 100644
--- a/app/lib/twitter_api/upserted_columns_hash/tweet_hash.rb
+++ b/app/lib/twitter_api/upserted_columns_hash/tweet_hash.rb
@@ -40,8 +40,8 @@ def all_columns(tweet_object, search_word: nil)
           text: kill_nil(tweet_object.attrs[:full_text]),
           search_word_id: kill_nil(search_word_id),
 
-          created_at: Time.now,
-          updated_at: Time.now
+          created_at: Time.zone.now,
+          updated_at: Time.zone.now
         }
       end
     end
diff --git a/app/lib/twitter_api/upserted_columns_hash/user_hash.rb b/app/lib/twitter_api/upserted_columns_hash/user_hash.rb
index 5edb32fa..98ec9df2 100644
--- a/app/lib/twitter_api/upserted_columns_hash/user_hash.rb
+++ b/app/lib/twitter_api/upserted_columns_hash/user_hash.rb
@@ -47,8 +47,8 @@ def all_columns(user_object)
           connections: kill_nil(user_object.connections, default_value: 'NOTHING'),
           email: kill_nil(user_object.email, default_value: 'NOTHING'),
 
-          created_at: Time.now,
-          updated_at: Time.now
+          created_at: Time.zone.now,
+          updated_at: Time.zone.now
         }
       end
     end
diff --git a/app/models/tweet.rb b/app/models/tweet.rb
index 65100ee0..8fd7fe9f 100644
--- a/app/models/tweet.rb
+++ b/app/models/tweet.rb
@@ -16,7 +16,7 @@ class Tweet < ApplicationRecord
   }
 
   tweeted_at_validation = {
-    tweeted_at: '2018-06-22 21:00:00'.in_time_zone('Tokyo')..'2018-06-24 09:59:59'.in_time_zone('Tokyo')
+    tweeted_at: ('2018-06-22 21:00:00'.in_time_zone('Tokyo'))..('2018-06-24 09:59:59'.in_time_zone('Tokyo'))
   }
 
   user_id = User.find_by(screen_name: 'gensosenkyo').nil? ? 0 : User.find_by(screen_name: 'gensosenkyo').id
@@ -30,7 +30,7 @@ class Tweet < ApplicationRecord
 
   # now_counting
   tweeted_at_validation_for_now_counting = {
-    tweeted_at: '2018-06-30 12:00:00'.in_time_zone('Tokyo')..'2018-07-01 23:59:59'.in_time_zone('Tokyo')
+    tweeted_at: ('2018-06-30 12:00:00'.in_time_zone('Tokyo'))..('2018-07-01 23:59:59'.in_time_zone('Tokyo'))
   }
 
   scope :now_counting_tweets_desc, lambda {
diff --git a/app/models/user.rb b/app/models/user.rb
index 88758416..e1e1ecdf 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -54,7 +54,7 @@ class User < ApplicationRecord
   def valid_condition_for_vote
     {
       is_retweet: 0,
-      tweeted_at: '2018-06-22 21:00:00'.in_time_zone('Tokyo')..'2018-06-24 09:59:59'.in_time_zone('Tokyo')
+      tweeted_at: ('2018-06-22 21:00:00'.in_time_zone('Tokyo'))..('2018-06-24 09:59:59'.in_time_zone('Tokyo'))
     }
   end