To maintain excellent cleaning performance by making developer recovered by cleaning reusable and avoiding the deformation of a cleaning blade.

In this image forming device having 1st and 2nd cleaning devices 13 and 14 for 1st and 2nd image carriers respectively, the devices 13 and 14 perform cleaning to remove and recover developer remaining on the 1st image carrier after primary transfer and the 2nd image carrier after secondary transfer after a developer image is formed on the surface of the 1st image carrier 1 by a developing device, primarily transferred to the 2nd image carrier 2, and secondarily transferred to transfer material from the 2nd image carrier, and the developer is obtained by externally adding and mixing at least a cleaning assistant in developer base substance. In the 2nd cleaning device 14, the cleaning is performed without recovering the cleaning assistant when the developer is recovered into the 2nd cleaning device from the 2nd image carrier, and the developer, from which the cleaning assistant has been removed and recovered, is returned to the developing device.