An image forming apparatus includes a plurality of image forming units arranged to form toner images of different colors on surfaces of photoconductive drums, an intermediate transfer unit that has an intermediate transfer belt arranged in the vicinity of the photoconductive drums and a plurality of intermediate transfer rollers opposed to the respective photoconductive drums through the intermediate transfer belt, and that transfers the toner images formed on the photoconductive drums to the intermediate transfer belt, and a transfer unit arranged to transfer, to a piece of paper, the toner images of different colors transferred to the intermediate transfer belt. The intermediate transfer unit includes a position setting mechanism arranged to move the intermediate transfer rollers individually to an operation position in which the roller makes contact with the intermediate transfer belt to be close to the photoconductive drum or to a stand-by position in which the roller is separated away from the intermediate transfer belt to be retreated from the photoconductive drum.