A plurality of heating units generates a heat by an alternating-current power supplied from a corresponding alternating-current power supply unit through a corresponding input terminal and supplying the heat to a fixing unit that fixes a toner image transformed on a recording paper by heating. A plurality of power control units controls the alternating-current power to a corresponding heating unit. A plurality of detecting units detects a reference phase of waveform of the alternating-current power. A control unit individually controls the power control units based on detected signals output from the detecting units.