A circuit pattern, which is a second negative electrode wiring, and a horizontally extending area of a circuit pattern, which is a first negative electrode wiring, are connected electrically and mechanically by a vertically extending area of the circuit pattern and wires, which are an inter-negative-electrode wiring. As a result, N terminals and N1 terminals are equal in potential in a semiconductor device. The N terminals of a converter circuit section and the N1 terminals of an inverter circuit section are electrically connected to make the N terminals and the N1 terminals equal in potential.