A semiconductor device includes: a package; two semiconductor chip fixing parts located adjacently to each other in the package; and first and the second semiconductor chips, each of which is fixed on the semiconductor chip fixing part and has a field effect transistor formed therein. A gate lead G1, a source lead S1, and a drain lead D2 are arranged from left to right on the first surface of the package and a drain lead D1, a source lead S2, and a gate lead G2 are arranged from left to right on the second surface. A gap between the source lead S1 and the drain lead D2 is two times a gap between the gate lead G1 and the source lead S1, and a gap between the drain lead D1 and the source lead S2 is two times a gap between the source lead S2 and the gate lead G2.