A full-color image forming apparatus for forming an image on a transfer material by transferring a toner image formed on an image bearing member onto the transfer material includes a belt-shaped transfer member for transferring a toner image from the image bearing member onto a transfer material, and a cleaning blade for cleaning the belt-shaped transfer member by being brought into contact therewith. Shape coefficients SF-1 and SF-2 of a toner for forming the toner image have values of 100≦SF-1≦125, and 100≦SF-2≦125, respectively. The belt-shaped transfer member has a seamless shape in which a seam is absent. An amount of abrasion of a surface of the belt-shaped transfer member is equal to or less than 10.0 mg. An angle of contact with respect to water of the belt-shaped transfer member is at least 60°. A slide resistance of a surface of the belt-shaped transfer member is equal to or less than 1 N.