A high frequency semiconductor amplifier includes an input circuit, a first semiconductor element, first bonding wires, an interstage circuit, second bonding wires, a second semiconductor element, third bonding wires, an output circuit, fourth bonding wires and a package. The input circuit includes a first DC blocking capacitor, an input transmission line, a first input pad part, and a first bias circuit. The interstage circuit includes a second DC blocking capacitor, an interstage transmission line, a first output pad part, and a second bias circuit, a microstrip line divider, and a second input pad part. The output circuit includes a second output pad part, a microstrip line combiner, a third DC blocking capacitor, an output transmission line, and a fourth bias circuit. The first and second semiconductor elements, the input circuit, the interstage circuit, and the output circuit are bonded to the package.

In a module, a metal member includes a right support portion, the right support portion has a right support foremost portion located at a foremost in the right support portion and located in front of the plate-shaped portion, the right support portion bends in a forward direction from a right boundary when the right support portion has the right support foremost portion, the right support portion bends in a backward direction and a right direction from the right support foremost portion when the right support portion has the right support foremost portion, and the right support portion is provided with a first lower notch extending in an upward direction from a lower side and overlapping the right support foremost portion when viewed in the up-down direction.