A steering roller autonomously steers an intermediate transfer belt. A pre-secondary-transfer roller is disposed at a position upstream of and adjacent to a driving roller also functioning as a transfer inner roller, and includes a rubber material on at least a surface thereof. This suppresses movement of the intermediate transfer belt even when a lateral-deviation converging position is changed by the change of position of the driving roller having large frictional force due to the pressing force of a secondary transfer roller. Hence, the belt deviation amount is reduced, and the time until lateral deviation converges is shortened.