PURPOSE: To securely recover opposite-polarity toner and paper powder, to prevent an image carrier from damaging and to eliminate the formation of a white stripe image, and to prevent a defect in cleaning and a toner scatter due to leakage of toner by applying an AC bias to a scavenging roller.

CONSTITUTION: This device is equipped with a fur brush 5 which collects residual toner on an electrostatic latent image carrier 1, the scavenging roller 6 which rotates in contact with the fur brush and collects toner caught by the fur brush, and a toner recovery member which recovers the toner on the scavenging roller. Then the AC bias is applied to the scavenging roller 6. Consequently, the collection of paper powder is made secure to suppress the formation of a white stripe image and the occurrence of a defect in cleaning, thereby reducing the toner scattering.