A semiconductor device that can detect temperature appropriately is provided. A semiconductor device provided with a semiconductor substrate in which one or more transistor portions and one or more diode portions are provided is provided, including: a temperature detecting portion provided above the top surface of the semiconductor substrate and having a longitudinal side in a predetermined longitudinal direction; a top surface electrode provided above the top surface of the semiconductor substrate; and one or more external lines that have a connecting part connected with the top surface electrode and electrically connect the top surface electrode to a circuit outside the semiconductor device. The temperature detecting portion extends across the one or more transistor portions and the one or more diode portions in the longitudinal direction, and the connecting part of at least one of the external lines is arranged around the temperature detecting portion when seen from above.