An image forming apparatus includes a drum unit which holds plural photosensitive drums, a developing cartridge which is provided for each photosensitive drum, a translation member which is provided to be movable linearly, and a movable member for each developing cartridge. The movable member includes a main body rotatably supported by the supporting shaft at one end portion thereof, an input portion provided at the other end portion thereof and to which a pressing force is input by the translation member with the linear movement thereof; an abutting portion which is provided between the one and other end portions of the main body, and abuts the drum unit while the movable member rotates about the supporting shaft; and an operating portion which applies to the supporting shaft a force for moving the developing cartridge as the movable member is rotated with the middle portion as a fulcrum.