A power amplifier includes: a distortion compensating circuit that causes a bias circuit to have an output impedance so that a subsequent block bipolar transistor for signal amplification-use has a maximized saturated output power; and a distortion compensating circuit that causes a bias circuit to have an output impedance so that a distortion of an output power of the power amplifier 1 with respect to an input power is canceled by a distortion characteristic of an output power with respect to an input power of the subsequent block bipolar transistor for signal amplification-use which has a maximized saturated output power and a distortion characteristic of an output power with respect to an input power of the preceding block bipolar transistor for signal amplification-use. This makes it possible to provide a power amplifier that allows reduction in saturated output power brought by realization of a highly efficient low-distortion power amplifier.