A semiconductor device, including a first semiconductor chip including a first substrate having a semiconductor larger in bandgap than silicon, the first semiconductor chip being formed with a first FET including a first gate electrode, a first source, and a first drain, a second semiconductor chip including a second substrate having a semiconductor larger in bandgap than silicon, the second semiconductor chip being formed with a second FET having a second gate electrode, a second source, and a second drain, and a third semiconductor chip including a third substrate having silicon, the third semiconductor chip being formed with a MOSFET including a third gate electrode, a third source, and a third drain. The first semiconductor chip and the second semiconductor chip are mounted over a first chip mounting section, and the third semiconductor chip is mounted over a second chip mounting section.