A semiconductor device including a radio-frequency amplifier circuit and a band selection switch are mounted on or in a module substrate. An output matching circuit includes at least one passive element disposed on or in the module substrate. The output matching circuit is coupled between the radio-frequency amplifier circuit and the band selection switch. The semiconductor device includes a first member having a semiconductor portion made of an elemental semiconductor and a second member joined to the first member in surface contact with the first member. The radio-frequency amplifier circuit including a semiconductor element made of a compound semiconductor is formed at the second member. The semiconductor device is disposed in close proximity to the output matching circuit in plan view. The output matching circuit is disposed in close proximity to the band selection switch.