Hello masanori oyama,

Sorry for late reply to this,
Yes, you can go to your media manager and click the button "Insert as gallery" . hope this help.
And make sure that your image size is to be same, so the result will shown out more better.

Hi Arlex,

Sorry for late reply.
Thank you for the advice.

I understand how to insert the gallery.
Regard to the thumbnails of the gallery, how do we set the image dimensions?

Hello masanori oyama,

You're welcome, unfortunately we do not have option for set the image dimensions If you're using the "insert the gallery" in your blog entry, if you're insert single image in your blog entry, you can edit the dimensions while you double click on the image from media manager. Hope this help.