To provide a high frequency amplifier so designed as to avoid the negative feedback from an output to an input, thereby improving the gain.

A parallel resonator circuit 30 comprises a parallel connected circuit of an inductor 31 and a capacitor 32, and is connected between the output of an input matching circuit 210 and the drain of an FET 10. The inductor 31 and the capacitor 32 have values selected so that a parallel connection circuit 130 of a gate-drain capacitance 11 with the resonator circuit 30 performs parallel resonance at a frequency f0 in a required frequency range for operating the high frequency amplifier.