diff --git a/app/services/memos_service.rb b/app/services/memos_service.rb
index a01305d2..e8816da0 100644
--- a/app/services/memos_service.rb
+++ b/app/services/memos_service.rb
@@ -792,7 +792,7 @@ class MemosService
       attachments.each do |attach|
         attachments_list << {:id => attach.id,
                              :title => attach.filename,
-                             :url => "/attachments/download/" + "#{attach.id}" + "/" + "#{attach.filename}",
+                             :url => "/attachments/download/" + "#{attach.id}" + "/" + "#{attach.filename}#{attach.is_pdf? ? "?disposition=inline" : ""}",
                              :filesize => number_to_human_size(attach.filesize,significant: false, precision: 2)}
       end
     end