A CPU selects which speed to execute a contact control of photosensitive drums and developing rollers of a plurality of process stations at, a normal speed or a speed higher than the normal speed. The CPU selects which speed to execute a separation control of the photosensitive drums and the developing rollers of the plurality of process stations at, a normal speed or a speed higher than the normal speed. The CPU further selects contact controls and separation controls so that a difference between the number of times of execution of the contact control at the speed higher than the normal speed and the number of times of execution of the separation control at the speed higher than the normal speed becomes less than or equal to a predetermined number of times.