The present disclosure, for the prevention of a possible degradation of an induction coil in insulating performance by preventing condensate formation on an induction coil, provides a device that is configured to include a roller main body, an induction heat generator provided in the roller main body and having the induction coil for heating the roller main body inductively, a cooling mechanism configured to introduce a coolant mist into a clearance portion between the roller main body and the induction heat generator for cooling the roller main body, an AC voltage application part configured to apply AC voltage to the induction coil, and a DC voltage application part configured to apply DC voltage to the induction coil.