An image forming apparatus is capble of selectively moving a plurality of developing devices to a developing position. During the moving operation of each developing device to the developing position, the moving distance of at least one developing device differs from the moving distance of the other developing devices. When the moving operation is performed during an ordinary image forming operation, the moving member is controlled so that the position of an image forming region on the image bearing member when the at least one developing device is at the developing position and the position of the image forming region on the image bearing member when the other developing devices is at the developing position may become substantially equal to each other.