To provide an image forming device having high extensibility allowing the mounting of other paper storage trays in hierarchical arrangement or a paper carrying device while improving paper aligning performance when used with only one paper storage tray.

The image forming device 1 comprises a paper storage part formed between an image reading part 5 located on the upper side and an image forming part 4 located on the lower side. A top plate 8 forming the image forming part 4 forms part of the paper storage tray 13. The paper storage tray 13 includes a turnable-down plate 2 mounted on the image forming part 4. The turnable-down plate 2 is stored in the storage part 10 in a turned-down state.