A cleaningless image forming apparatus of the present invention uses spherical toner grains on surfaces of which a charge control agent and/or organic fine grains are present, thereby enhancing efficient image transfer. A brush roller collects, among toner grains left on a photoconductive drum after image transfer, toner grains of polarity opposite to preselected polarity and then releases them to the drum at preselected timing. The toner grains of opposite polarity are then transferred to an intermediate image transfer belt. When the toner grains of opposite polarity pass a charging zone assigned to a charge roller, a bias to the charge roller is interrupted or the charge roller is released from the drum.