In a mobile communication device, a power amplifier amplifies the power of a signal to be transmitted. A transmitter filter limits the frequency band of the amplified signal to a predetermined frequency band for transmission. The signal limited in frequency band is transmitted via an antenna. Output power control circuitry controls the output power of the signal to be transmitted and has an output power sensor and an automatic power control circuit. The output power sensor succeeds the transmitter filter in the direction of flow of the signal to be transmitted, and senses the output power of the signal. The automatic power control circuit controls the gain of the power amplifier such that the output power sensed by the output power sensor coincides with a preselected reference value.