To simplify the configuration in a conventional circuit and obtain a similar effect with a further inexpensive configuration.

In a device which has a heater 3 to generate a heat by supplying electricity of alternating-current from a power supply, a switching means 4 that makes the heater 3 on and off, a zero cross detection circuit 9 that detects the zero cross of the alternating-current power supply, a signal generation circuit 10 for phase control to generate signals in order to apply electricity into the heater 3 by phase control, and which is supplied of electricity to the heater 3 by phase control in a predetermined period (t1) at the starting time of applying electricity and which is supplied of electricity to the heater 3 by the zero cross after the predetermined period (t1), a timer circuit 5, a reference voltage means 11a and a comparator 6 that compares an output Va of the timer circuit 5 and an output Vref of the reference voltage means 11a, and based on the output Vzero of the zero cross detection circuit, the device is constituted so that the reference voltage means Vref is made to change in the reference voltage means 11a.