A transfer flow-in current which flows from a transferring device into an image carrier, a separation flow-in current which flows from a separating device into the image carrier, an aperture width in the recording member transporting direction of an aperture of the transferring device, and an aperture width in the recording member transporting direction of an aperture of the separating device are set so as to have the relationship: separation flow-in current=transfer flow-in current×(transfer aperture width/separation aperture width).