A power control unit for high-frequency dielectric heating is provided. The power control includes an input current detection section for detecting input current from an AC power supply to an inverter circuit and outputting input current waveform information. A conversion section converts the input current waveform information into a drive signal of the switching transistor of the inverter circuit so that instantaneous fluctuation of the input current waveform information is suppressed. An input voltage detection section detects input voltage from the AC power supply to the inverter circuit and outputs input voltage waveform information. A selection section selects the input current waveform information or the input voltage waveform information, whichever is larger. The conversion section also converts the selected input current waveform information or input voltage waveform information into the drive signal of the switching transistor of the inverter circuit.