An image forming apparatus includes a translation cam having a cam surface configured to move a developing roller from a contact position contacting a photosensitive member to a retracted position retracted from the photosensitive member and further having a holding surface configured to hold the developing roller at the retracted position. The image forming apparatus further includes a first engaging portion. The translation cam includes a second engaging portion. The first engaging portion and the second engaging portion are configured to engage each other before a functioning surface of the translation cam is switched from the holding surface to the cam surface.