A high-frequency power amplifier includes a transistor which is inputted with a high-frequency signal, amplifies the high-frequency signal and outputs the same; a fundamental-signal matching circuit, one end of which is connected to an output of said transistor and which matches at least the impedance of fundamental signal in the amplified high-frequency signal and outputs the same from the other end; a power supply which supplies electric power to said transistor from a node located in an interval from the output of said transistor to said fundamental-signal matching circuit; a first inductor, one end of which is connected to said power supply; a second inductor connected in series between the other end of said first inductor and said node; and a first capacitor, one end of which is connected between said first inductor and said second inductor while the other end thereof is connected to a reference potential, said first capacitor forming a first series-resonant circuit with said second inductor and a parallel-resonant circuit with said first inductor.