An image forming apparatus includes an elastic member applying an urging force to a drum cartridge toward an upstream side of a mounting direction of the drum cartridge against a mounting operation thereof, and an engaging portion engaging with the drum cartridge receiving the urging force to restrict movement of the drum cartridge from a mounted position toward the upstream side in the mounting direction. The drum cartridge includes a release member for releasing engagement between the drum cartridge and an engaging portion, wherein the drum cartridge is moved to a predetermined position in an upstream side of the mounting position with respect to the mounting direction by receiving the urging force upon release of the engagement between the drum cartridge and the engaging portion, and the drum cartridge positioned at a predetermined position contacts a rotatable member subjected to a closing operation to restrict rotation of the rotating member.