A pair of meander regulating rollers are disposed on the paper input side at both the longitudinal ends of a fixing roller. If a fixing belt moves off to one side end from the correct position, the meander regulating roller arranged on the one side end presses the fixing belt so as to produce a force of moving the belt to the other side end, whereby the fixing belt is stabilized in a state where the belt is held by the meander regulating roller on the one side end. On the other hand, if the fixing belt moves off to the opposite side end due to uneven temperature distribution, imbalance nip load or the like in the axial direction, it is possible to restrain the meandering in a similar manner by means of the meander regulating roller on the other side end.