Image forming apparatus including toner cartridge that is detachable from housing with drum cartridge kept attached to housing

An image forming apparatus comprising:

• a housing having an opening providing a first region and a second region;
• a first cover movable between a first closed position closing the first region and a first open position opening the first region;
• a second cover movable between a second closed position closing the second region and a second open position opening the second region;
• a drum cartridge comprising a photosensitive drum, the drum cartridge being attachable to and detachable from the housing in a first direction through the first region in a state where the first cover is at the first open position;
• and
• a toner cartridge configured to accommodate toner therein and detachably attachable relative to the drum cartridge, the toner cartridge comprising a part movable between a first position and a second position in a state where the toner cartridge is attached to the drum cartridge, the toner cartridge being unable to be detached from the drum cartridge when the part of the toner cartridge is at the first position and the toner cartridge being detachable from the drum cartridge when the part of the toner cartridge is at the second position, the toner cartridge being attachable to and detachable from the drum cartridge attached to the housing through the second region in a second direction crossing the first direction in a state where:
• the first cover is at the first closed position;
• the second cover is at the second open position;
• and the part of the toner cartridge is at the second position,
• wherein the part of the toner cartridge is movable in a third direction from the first position to the second position, the third direction crossing the first direction and the second direction.