An image forming apparatus in which a developing device for developing a latent image is exchangeable includes an opening for permitting mounting and dismounting of the developing device relative to a main assembly of the image forming apparatus, a path along which the developing device is movable between the opening and a predetermined position in the main assembly, a movable door for opening and closing the opening, and a device for mechanically coupling the door and developing device to move the developing device along the path in association with opening and closing action of the door.