A high frequency power amplifying apparatus includes a power supply device for a high frequency power amplifying circuit, an RF signal processing circuit, and a high frequency power amplifying circuit. Bidirectional converters supplying and/or regenerating an electric charge are provided between an input section of an input voltage and an output section of an output voltage. A converter controlling circuit detects an envelope of an RF input signal, and sets and switches resonant frequencies and amplitudes of the bidirectional converters such that the output voltage follows an amplitude change of an envelope input signal. A delay time detecting circuit detects a delay time of the power supply device for a high frequency power amplifying circuit and makes an adjustment through a delay adjusting circuit.