An image forming apparatus includes an all contact full color mode and an all contact monochrome mode. During an image forming job in which image forming is successively performed on a plurality of recording materials, in case that an image is formed using only the first image forming unit with the first image forming unit and the second image forming unit being in contact with the intermediate transfer member after an image has been formed using both of the first image forming unit and the second image forming unit, the controller determines whether the all contact full color mode or the all contact monochrome mode is performed based on an image forming speed to be performed or other criteria.