An image forming apparatus includes multiple image forming units disposed adjacent to and horizontally aligned with each other to form respective single non-black color images, a first transfer member to sequentially transfer and overlay the respective single non-black color images thereon for forming a composite color image, a black image forming unit disposed separately from the multiple image forming units including a black image carrier and a black image developing unit, a second transfer member to transfer the black image from the black image forming unit onto a recording medium, a first cleaning unit to clean the surface of the black image carrier, and a second cleaning unit to clean the surface of the second transfer member. The black toner removed from the surface of the black image carrier is collected to the black image developing unit.