An image forming apparatus includes: a housing; a cover; a developing cartridge; and a drum cartridge including a drum frame, a photosensitive drum, a pressing member configured to press the developing roller to the photosensitive drum in a state where the developing cartridge is mounted to the drum frame, and a lock lever, the drum cartridge being mountable to an inside of the housing in a state where the developing cartridge is mounted to the drum cartridge, wherein in a state where the cover moves from the closed position to the opened position, the lock lever moves from a locked position at which the developing cartridge is prevented from being demounted from the drum frame to a non-locked position at which the developing cartridge is allowed to be demountable from the drum frame.