diff --git a/app/controllers/fluentd/settings/histories_controller.rb b/app/controllers/fluentd/settings/histories_controller.rb
index c789a36..a02a622 100644
--- a/app/controllers/fluentd/settings/histories_controller.rb
+++ b/app/controllers/fluentd/settings/histories_controller.rb
@@ -1,7 +1,7 @@
 class Fluentd::Settings::HistoriesController < ApplicationController
   before_action :login_required
   before_action :find_fluentd
-  before_action :find_backup_file, only: [:show, :reuse]
+  before_action :find_backup_file, only: [:show, :reuse, :configtest]
 
   def index
     @backup_files = @fluentd.agent.backup_files_in_new_order.map do |file_path|
@@ -17,6 +17,16 @@ class Fluentd::Settings::HistoriesController < ApplicationController
     redirect_to daemon_setting_path, flash: { success: t('messages.config_successfully_copied',  brand: fluentd_ui_brand) }
   end
 
+  def configtest
+    @fluentd.config_file = @backup_file.file_path
+    if @fluentd.agent.dryrun
+      flash = { success: t('messages.dryrun_is_passed') }
+    else
+      flash = { danger: @fluentd.agent.log_tail(1).first }
+    end
+    redirect_to daemon_setting_history_path(params[:id]), flash: flash
+  end
+
   private
 
   def find_backup_file
diff --git a/app/views/fluentd/settings/histories/show.html.haml b/app/views/fluentd/settings/histories/show.html.haml
index ace0457..27f7899 100644
--- a/app/views/fluentd/settings/histories/show.html.haml
+++ b/app/views/fluentd/settings/histories/show.html.haml
@@ -1,5 +1,10 @@
-- page_title t('.page_title', label: @fluentd.label) do
-  - link_to reuse_daemon_setting_history_path(id: @backup_file.file_id), method: 'post', class: "btn btn-primary pull-right" do
+- page_title t('.page_title', label: @fluentd.label)
+
+%p{class: "pull-right"}
+  = link_to configtest_daemon_setting_history_path(id: @backup_file.file_id), method: "post", class: "btn btn-default" do
+    = icon('fa-legal')
+    = t("terms.configtest")
+  = link_to reuse_daemon_setting_history_path(id: @backup_file.file_id), method: 'post', class: "btn btn-primary" do
     = icon('fa-pencil')
     = t("terms.reuse")
 
diff --git a/app/views/shared/_flash.html.haml b/app/views/shared/_flash.html.haml
index 3da9db9..be490b7 100644
--- a/app/views/shared/_flash.html.haml
+++ b/app/views/shared/_flash.html.haml
@@ -8,3 +8,6 @@
   - if flash[:info]
     %p.alert.alert-info
       =raw flash[:info]
+  - if flash[:danger]
+    %p.alert.alert-danger
+      =raw flash[:danger]
diff --git a/config/locales/translation_en.yml b/config/locales/translation_en.yml
index de25bf3..a9b6d5a 100644
--- a/config/locales/translation_en.yml
+++ b/config/locales/translation_en.yml
@@ -13,6 +13,7 @@ en:
     fluentd_status_stopped: Stopped
     config_successfully_copied: "Config has been copied successfully. Please restart %{brand} to use the new config"
     note_updating_success: "Note successfully updated."
+    dryrun_is_passed: Success without errors.
 
   terms: &terms
     name: Name
@@ -64,6 +65,7 @@ en:
     backup_time: Backed up at
     note: Note
     reuse: reuse
+    configtest: config test
 
   plugins:
     view_on_rubygems_org: View on rubygems.org
diff --git a/config/locales/translation_ja.yml b/config/locales/translation_ja.yml
index 6d572be..8755c4d 100644
--- a/config/locales/translation_ja.yml
+++ b/config/locales/translation_ja.yml
@@ -13,6 +13,7 @@ ja:
     fluentd_status_stopped: 停止中
     config_successfully_copied: "設定をコピーしました。反映させるには、 %{brand}を再起動してください。"
     note_updating_success: "メモを更新しました。"
+    dryrun_is_passed: 使用可能です
 
   terms: &terms
     name: アカウント名
@@ -64,6 +65,7 @@ ja:
     backup_time: バックアップ日時
     note: メモ
     reuse: 再利用
+    configtest: 設定テスト
 
   plugins:
     view_on_rubygems_org: rubygems.orgで見る
diff --git a/config/routes.rb b/config/routes.rb
index 42ea789..f54dbd4 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -66,6 +66,7 @@ Rails.application.routes.draw do
 
         resources :histories, only: [:index, :show], module: :settings, controller: :histories do
           post "reuse", action: 'reuse', on: :member, as: 'reuse'
+          post "configtest" , action: "configtest", on: :member, as: "configtest"
         end
 
         resources :notes, only: [:update], module: :settings, controller: :notes
diff --git a/spec/features/fluentd/setting/hisotries_spec.rb b/spec/features/fluentd/setting/hisotries_spec.rb
index a8de6db..e227d71 100644
--- a/spec/features/fluentd/setting/hisotries_spec.rb
+++ b/spec/features/fluentd/setting/hisotries_spec.rb
@@ -44,5 +44,44 @@ describe "histories", stub: :daemon do
       page.should have_text(I18n.t('messages.config_successfully_copied', brand: 'fluentd') )
       page.should have_text(last_backup_file.content)
     end
+
+    describe "configtest" do
+      let(:daemon) { build(:fluentd, variant: "fluentd_gem") } # To use fluentd_gem for real dry-run checking
+      before do
+        daemon.agent.config_write config
+        daemon.agent.config_write "# dummy"
+        backup = Fluentd::SettingArchive::BackupFile.new(daemon.agent.backup_files_in_new_order.first)
+        visit "/daemon/setting/histories/#{backup.file_id}"
+        click_link I18n.t("terms.configtest")
+      end
+
+      context "invalid configfile" do
+        let(:config) { <<-CONFIG }
+        <source>
+          type aaaaaaaaaaaa
+        </source>
+        CONFIG
+
+        it do
+          page.should_not have_css('.alert-success')
+          page.should have_css('.alert-danger')
+          page.should have_text(%Q|Unknown input plugin 'aaaaaaaaaaaa'|)
+        end
+      end
+
+      context "valid configfile" do
+        let(:config) { <<-CONFIG }
+        <source>
+          type syslog
+          tag syslog
+        </source>
+        CONFIG
+
+        it do
+          page.should have_css('.alert-success')
+          page.should_not have_css('.alert-danger')
+        end
+      end
+    end
   end
 end