A semiconductor device is equipped with an element region, an electrode, a thermal conduction portion, and a protective membrane. The element region is equipped with a plurality of gate electrodes. The electrode is formed on a surface of the element region. The thermal conduction portion is located on a surface side of a central portion of the electrode, and is higher in thermal conductivity than the element region. The protective membrane is formed on a peripheral portion that is located on the surface side of the electrode and surrounds a periphery of the central portion. In the element region, an emitter central region that is formed on a back side of the central portion of the electrode remains on for a longer time than an emitter peripheral region that is formed on a back side of the peripheral portion of the electrode.