An image forming apparatus includes an image bearing member unit having an image bearing member, a developing unit including a developer carrying member configured to form a toner image on the image bearing member, and a moving mechanism configured to move the developing unit in interrelation with opening and closing of an openable member. In addition, a moving portion moves the image bearing member unit between a mounting position and a predetermined position a predetermined distance away from the mounting position in an upstream direction with respect to the inserting direction, with the moving portion capable of moving the image bearing member unit to the predetermined position or to a position upstream of the predetermined position with respect to the inserting direction.