An image forming apparatus having therein an image carrier, an intermediate transfer belt is trained about plural rollers and is located at a position where it comes in contact with the image carrier, a primary transfer roller that is arranged to face the image carrier through the intermediate belt for the purpose of transferring toner on the image carrier onto the intermediate transfer belt, wherein the following expression holds when Ft (kgf) represents tension of the intermediate transfer belt, Fr (kgf) represents pressing force of primary transfer roller and d (mm) represents a shift amount for the image carrier and the primary transfer roller,