In an image forming apparatus, a plurality of photoconductors arranged in the apparatus is supported by a support frame which is allowed to be pulled out from a body of the apparatus; and an endless intermediate transfer belt looped around a first roller and a second roller is in contact with each of the plurality of photoconductors. The first roller is supported by the body of the apparatus and retained in a position fixed relative to the body of the apparatus, and the support frame comprises a positioning portion which is configured to support a roller shaft of the second roller or a bearing part of the roller shaft of the second roller and to retain the intermediate transfer belt in a position fixed relative to the plurality of photoconductors.