To reduce the current consumption of a high frequency power amplifier and a harmonic spurious level of a transmission output power by reducing a loss resulting from extracting part of a fundamental component of the transmission output of the high frequency power amplifier.

In the case that a designated transmission output power level is high, a power detection coupling degree of a power detection frequency of a power detection means 3 is selected by means of a power detection frequency band selection signal 7 to detect selectively a frequency of a harmonic component without detecting the fundamental wave component of the transmission output power. In the case that the designated transmission output power level is low, a fundamental frequency band of the transmission output power is selected as a power detection frequency band, part of the fundamental component of the transmission output power is detected, a detection means 4 converts it into a transmission output power detection signal, a gain control section obtained by comparing the transmission output power detection signal and the transmission output control reference signal 6 at an error amplifier means 5 is fed to the high frequency power amplifier 2 to control the transmission output power level to a designated level.