A semiconductor device including a semiconductor substrate in which a diode region and an IGBT region are formed is provided. In the semiconductor device, the diode region includes a second conductivity type cathode layer. An impurity concentration of second conductivity type impurities of the cathode layer is distributed in a curve pattern having at least two peaks, and the impurity concentration of the second conductivity type impurities is higher than that of first conductivity type impurities at all depths of the cathode layer.