PURPOSE: To reduce the abrasion of the rotary shafts, bearings, etc., of a toner carrying means carrying waste toner discharged from a cleaning device and a developer carrying means carrying a waste developer discharged from a developing vessel by driving both the carrying rollers at low speed at the time of forming an image and at high speed at the time of discharging a developer.

CONSTITUTION: A driving part 20 for the toner carrying means (waste toner carrying screw) 14 and the developer carrying means (waste developer carrying screw) 15 is controlled so as to set carrying speed at the time of discharging the developer higher than that at the time of copying. In the copying, the waste toner discharged from the cleaning device 2 is carried to a recovering container 18 by the waste toner carrying screw 14. At this time, the waste toner carrying screw is driven at a low speed. When the developer is discharged, the developer discharged from the developing vessel 3 is carried to the recovering container 18 by the waste developer carrying screw 15. At this time, it is driven at a high speed to attain quick discharging.