A plurality of process cartridges, each including an electrophotographic photosensitive drum, and a process device actable on the photosensitive drum, are detachably mountable to an electrophotographic image forming apparatus for forming an image of a recording medium. The image forming apparatus includes an opening and closing member; an intermediate transfer member or a recording medium bearing member provided in the opening and closing member such that the intermediate transfer member can face the process cartridges under a condition in which the opening and closing member is closed, and the intermediate transfer member can be separated from the process cartridges under a condition in which the opening and closing member is open; and a moving guide for holding the process cartridges. The moving guide is moved in interlocking relationship with a closing motion of the opening and closing member from a load position, to which the process cartridges are loaded, to a mount position, in which the process cartridges are capable of performing an image forming operation, such that the process cartridges mounted to the load position can be moved to the mount position.