To prevent paper from being uselessly consumed along with batch output in an image forming device provided with a batch outputting function.

The image forming device 1 has a batch outputting function for outputting together data of a plurality of images sent from outside, at predetermined timing, and is provided with a memory 5, a controller 7, and an outputting section 13. The memory 5 sequentially stores the image data from the outside. The controller 7 overwrites first image data with a content of second image data when the second image data having the same file name as the first image data previously stored in the memory 5, is sent. The outputting section 13 outputs image data stored in the memory 5 together at the predetermined timing.