An image forming apparatus includes a housing, a drawer, and a process cartridge attachable to the drawer. The drawer can be drawn out of the housing toward one side in a first direction. The process cartridge includes: a process housing; a photosensitive drum rotatable about an axis extending in a second direction; a developing roller movable between a separated position and a contacting position relative to the photosensitive drum; and a locking member. The locking member is movable between a locking position for locking the developing roller at the separated position and an unlocking position for allowing the developing roller to move to the contacting position. The process cartridge is configured to contact a first surface of the drawer to be guided toward an attachment position on the drawer while the locking member is at the locking position during attachment of the process cartridge to the drawer.