A semiconductor device comprises a power device, a sensor which measures a physical state of the power device to transmit a signal according to the physical state, and a main electrode terminal through which a main current of the power device flows. The semiconductor device further comprises a sensor signal terminal connected to the sensor for receiving a signal from the sensor, a driving terminal which receives driving power for driving the power device, and an open bottomed case which houses the power device, the sensor, the main electrode terminal, the sensor signal terminal and the driving terminal. The first and second terminals electrically conduct with each other to form a double structure. Also, the sensor signal terminal and the driving terminal each have a first terminal and a second terminal which are not embedded within the case.