An image forming apparatus includes an image bearing member; a developing device for forming a toner image on the image bearing member while carrying a developer on a developer carrying member, wherein the developing device is mountable and demountable relative to a main assembly of the apparatus in a direction substantially parallel with a radial direction of the image bearing member; an urging mechanism for urging the developing device toward the surface of the image bearing member; and a moving mechanism, movable in a movement path of the developing device, for moving the developing device between a developing position in which development can be effected and a retracted position retracted from the developing position in a state in which the developing device is urged by the urging mechanism. The moving mechanism is temporarily retracted from an inside of the movement path of the developing device to an outside of the movement path of the developing device by a mounting and demounting operation of the developing device.