A semiconductor device includes a stepwise impurity layer provided at one of an anode portion and an cathode portion of the semiconductor device by introducing an impurity of a predetermined conduction type from a major surface of the semiconductor substrate through to a first depth to provide a first region of the semiconductor substrate having the impurity of the predetermined conduction type introduced therein. The predetermined conduction type is a same conduction type as a conduction type of the one of the anode portion and the cathode portion. The stepwise impurity layer is further provided by melting a second, predetermined region of the semiconductor substrate having a second depth deeper than the first depth and including the first region to make uniform the impurity of the predetermined conduction type in a concentration from the major surface through to the second depth to provide a uniform stepwise impurity concentration profile.