An image forming apparatus includes: a housing; a process cartridge including a photoconductive drum and a developing roller; a toner cartridge containing toner; and a drawer movable between an inner position and an outer position. The process cartridge includes a lock member movable between a lock position at which the lock member locks the process cartridge to the drawer, and a release position at which a lock between the process cartridge and the drawer is released. The lock member is located at the lock position in a state in which the process cartridge is mounted to the drawer, and the toner cartridge is mounted to the process cartridge. The lock member is located at the release position in a state in which the process cartridge is mounted to the drawer, and the toner cartridge is removed from the process cartridge.