An image forming apparatus includes: an endless belt; a plurality of image
carriers; a plurality of charging units; an exposing unit; and a
plurality of developing units configured to develop an electrostatic
latent image on each of the image carrier with a developer of different
color to form a developer image and to retrieve a residual developer on
the image carrier, wherein the endless belt is configured to be
transferred the developer images formed on each of the plurality of image
carriers thereon to form a color image, and transfers the color image
onto a recording medium, and wherein the developing unit provided at a
most upstream position with respect to the moving direction of the
endless belt forms the developer image with a developer of black color,
and is configured to retrieve a residual developer on the endless belt.