In a monochromatic print mode, an abutting timing on when a secondary transfer roller abuts on an intermediate transfer belt is different from the timing in a color print mode. Specifically, in the monochromatic print mode, the secondary transfer roller abuts on the intermediate transfer belt prior to the start of an exposure process for the first image. Then, the secondary transfer roller is separated from the intermediate transfer belt at completion of the secondary transfer of the final image. Therefore, the secondary transfer roller has already abutted on the intermediate transfer belt at the start of the irradiation of a light beam for forming the first electrostatic latent image. The exposure process is performed with the secondary transfer roller kept abutting on the intermediate transfer belt.