PURPOSE: To prevent the intrusion of residual toners into a developing device by adopting a blade cleaning system in a color image forming device of a drum color superposing system.

CONSTITUTION: A cleaning blade 13 is provided in the downstream of the transfer position of a photosensitive body 2. A bias roller 14 is disposed in the downstream of the cleaning blade 13. A recovering blade 15 is brought into contact with the bias roller 14. The cleaning blade is pressed to a photosensitive body 2 after transfer and a bias of the polarity reverse from the polarity of the residual toners 12 is impressed to the bias roller 14. The static electricity of the past residual toners 12 is removed by the bias roller 14 by squeezing the residual toners 12 on the photosensitive body 2 by the cleaning blade.