To realize a package in a state where a cartridge is attached to an image forming apparatus main body by adding a simple pressing member with a simple attachment.

The attachable/detachable hard cartridge pressing member realizing the loading/unloading of the cartridge while it is attached to the cartridge is arranged at least at either of positions opposed to a transfer roller in the cartridge, and fixes the outside case position of the cartridge. By loading the cartridge in the image forming apparatus main body in a state where the cartridge pressing member is attached to the cartridge, a transfer roller pressing part in the cartridge pressing member presses transfer bearings attached to both ends of the transfer roller, whereby a fixed gap is formed between a photoreceptor drum in the cartridge and the transfer roller. The packing form of the image forming apparatus is thus characterized.