diff --git a/app/views/seminars/show_data.html.erb b/app/views/seminars/show_data.html.erb
index 13fea7c..4e3811f 100644
--- a/app/views/seminars/show_data.html.erb
+++ b/app/views/seminars/show_data.html.erb
@@ -20,7 +20,7 @@
       <th class="seminarive-title-field"><%= t(:category) %></th>
       <td class="seminarive-title-value"><%= @seminar.category.title %></td>
     </tr>
-    <tr>
+    <tr <%= 'class="hidden"'.html_safe if @seminar_time_range.blank? %>>
       <th class="seminarive-title-field"><i class="fa fa-calendar fa-fw"></i><%= t('seminar.event_during') %></th>
       <td class="seminarive-title-value"><%= @seminar_time_range %></td>
     </tr>
@@ -40,7 +40,7 @@
       <td class="seminarive-title-value"><%= nl2br(@seminar.content) %></td>
     </tr>
     <% end %>
-    <tr>
+    <tr <%= 'class="hidden"'.html_safe if @sign_up_time_range.blank? %>>
       <th class="seminarive-title-field"><i class="fa fa-calendar fa-fw"></i><%= t('seminar.signup_during') %></th>
       <td class="seminarive-title-value"><%= @sign_up_time_range %></td>
     </tr>