A power control unit for a high-frequency dielectric heating for controlling an inverter for driving a magnetron wherein a series circuit made up of at least one set or more of at least two semiconductor switching elements (203,204), a resonance circuit, and a leakage transformer are connected to a DC power supply provided by rectifying a voltage of an AC power supply, a switching frequency of the semiconductor switching element (203,204) is modulated to be converted into high-frequency power, and output occurring on the secondary side of the leakage transformer is applied to the magnetron for energizing the magnetron, the power control unit for a high-frequency dielectric heating comprising: an input current detection section (271,286) which detects an input current input to the inverter from the AC power supply and outputs input current waveform information; an input voltage detection section (246,247) which detects an input voltage input to the inverter from the AC power supply and outputs input voltage waveform information; an addition section for adding the input current waveform information and the input voltage waveform information; and a conversion section (282,283) which converts the input current waveform information and the input voltage waveform information, which are added, into a drive signal of the switching element (203, 204) of the inverter; wherein the addition section includes a mixer being connected between the input current detection section (271,286) and the conversion section (282,283) to mix the input current waveform information, the input voltage waveform information, and power control information for controlling so that the current or the voltage at an arbitrary point of the inverter becomes a predetermined value to generate a switching frequency control signal, and the conversion section (282,283) is adapted to convert the switching frequency control signal into the drive signal so as to suppress the peak of the voltage applied to the magnetron. an input current detection section (271,286) which detects an input current input to the inverter from the AC power supply and outputs input current waveform information; an input voltage detection section (246,247) which detects an input voltage input to the inverter from the AC power supply and outputs input voltage waveform information; an addition section for adding the input current waveform information and the input voltage waveform information; and a conversion section (282,283) which converts the input current waveform information and the input voltage waveform information, which are added, into a drive signal of the switching element (203, 204) of the inverter; wherein the addition section includes a mixer being connected between the input current detection section (271,286) and the conversion section (282,283) to mix the input current waveform information, the input voltage waveform information, and power control information for controlling so that the current or the voltage at an arbitrary point of the inverter becomes a predetermined value to generate a switching frequency control signal, and the conversion section (282,283) is adapted to convert the switching frequency control signal into the drive signal so as to suppress the peak of the voltage applied to the magnetron.