diff --git a/Gemfile b/Gemfile
index 84fbd18..65e6adb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -17,6 +17,7 @@ gem 'rails-i18n'
 gem 'rails_config'
 gem 'jquery-fileupload-rails'
 gem 'carrierwave'
+gem 'rmagick'
 gem 'devise'
 ## 認可ライブラリ
 gem 'cancancan', '~> 1.7'
diff --git a/Gemfile.lock b/Gemfile.lock
index c06d66f..438d511 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -238,6 +238,7 @@ GEM
     ref (1.0.5)
     responders (1.0.0)
       railties (>= 3.2, < 5)
+    rmagick (2.13.2)
     rspec (2.14.1)
       rspec-core (~> 2.14.0)
       rspec-expectations (~> 2.14.0)
@@ -358,6 +359,7 @@ DEPENDENCIES
   rails_config
   rb-fsevent
   redcarpet
+  rmagick
   rspec-rails
   sass-rails (~> 4.0.2)
   selectize-rails
diff --git a/app/uploaders/answer_file_uploader.rb b/app/uploaders/answer_file_uploader.rb
index 65faf24..c2bff18 100644
--- a/app/uploaders/answer_file_uploader.rb
+++ b/app/uploaders/answer_file_uploader.rb
@@ -1,9 +1,15 @@
 # encoding: utf-8
 
 class AnswerFileUploader < CarrierWave::Uploader::Base
+  include CarrierWave::RMagick  
+
   # Choose what kind of storage to use for this uploader:
   storage :file
 
+  version :thumb do
+    process resize_to_fit: [200, 200]
+  end
+
   # Override the directory where uploaded files will be stored.
   # This is a sensible default for uploaders that are meant to be mounted:
   def store_dir
diff --git a/app/views/answers/_viewer.html.erb b/app/views/answers/_viewer.html.erb
index 24d35c6..97de01b 100644
--- a/app/views/answers/_viewer.html.erb
+++ b/app/views/answers/_viewer.html.erb
@@ -20,7 +20,7 @@
                   <% if file_form.object.is_pdf? %>
                     PDF
                   <% else %>
-                    <%= image_tag file_form.object.image.url %>
+                    <%= image_tag file_form.object.image.url(:thumb) %>
                   <% end %>
                 </a>
               </li>
@@ -39,7 +39,7 @@
               PDFを開く
             <% end %>
           <% else %>
-            <%= image_tag file.image.url, id: "file_#{file.id}" %>
+            <%= link_to image_tag(file.image.url(:thumb), id: "file_#{file.id}"), file.image.url, target: ['_blank'] %>
           <% end %>
         <% end %>
       </div>