PURPOSE: To obtain a best matching state at all times independently of a change in a transmission power by providing an impedance matching circuit to the communication equipment to select the matching state.

CONSTITUTION: The impedance matching circuit 4 is adjusted so that the matching is maximized when the transmission power of an amplifier processing section 2 is large (e.g., 1W). Moreover, the impedance matching circuit 4 is adjusted so that the matching is best when the transmission power of the amplifier processing section 2 is small (e.g., 63mW). When the transmission power is large, changeover switches 3, 6 are controlled to be thrown to the position of the impedance matching circuit 4 and when the transmission power is small, the changeover switches 3, 6 are controlled to be thrown to the position of the impedance matching circuit 5. The proper matching state is obtained by allowing the user to operate the changeover switches 3,6, a loss to be caused in a conventional equipment is eliminated and the efficiency is improved.