A first transistor chip (3) includes a first drain pad (5). A second transistor chip (4) includes a second drain pad (6). A transmission line (9) and a first capacitor (C1) are formed on a resin substrate (1). A first bonding wire (7) connects the first drain pad (5) and one end of the transmission line (9). A second bonding wire (10) connects the second drain pad (6) and one end of the first capacitor (C1). An output terminal (OUT) is connected to the other end of the transmission line (9) and the other end of the first capacitor (C1). A capacitance value of the first capacitor (C1) is selected so as to cause resonance with inductance of the second bonding wire (10).