A power amplifier

PURPOSE: A power amplifier is provided, which reduces power consumption and has maximum efficiency in a maximum power consumption area and a maximum usage frequency area. CONSTITUTION: An impedance matcher is installed on a power control path between an input stage and an output stage, and performs input matching and output matching. Amplifiers(20,22,24,26) are installed between the impedance matcher. And a control circuit(10) generates a path control signal on the ground of an antenna output signal from the external and then controls the power control path. The impedance matcher is installed on each of a number of power control paths in parallel each other, and only one power control path among the power control paths is used where one impedance matcher selected by the path control signal of the control circuit is installed.