In a high frequency power amplifier circuit that supplies a bias to an amplifying FET by a current mirror method, scattering of a threshold voltage Vth due to the scattering of the channel impurity concentration of the FET, and a shift of a bias point caused by the scattering of the threshold voltage Vth and a channel length modulation coefficient .lamda. due to a short channel effect are corrected automatically. The scattering of a high frequency power amplifying characteristic can be reduced as a result.
