A photosensitive cartridge attachable to/detachable from a main body of an image forming apparatus includes a photosensitive member, an attachment unit configured to removably attach a developing cartridge including a developing member that develops a latent image formed on the photosensitive member to the photosensitive cartridge, and a locking member configured to prevent disengaging of the developing cartridge from the attachment unit when the developing cartridge is attached to the attachment unit, wherein the locking member comes into contact, when the photosensitive cartridge to which the developing cartridge has been attached is attached to the main body of the image forming apparatus, with a main body contact member provided to the main body and electrically connects the main body contact member and the developing cartridge.