In particular, in the n?-type drift layer 3, a portion (hereinafter, concentration compensated region) in which the n-type doping concentration is compensated in a decreasing direction by vanadium is the n?-type lifetime reduced layer 22. Therefore, as depicted in FIG. 4, the depth distribution of the n-type doping concentration of the n?-type drift layer 3 that extends to a predetermined depth in a direction from the pn junction surface 12 between the p-type anode layer 4 and the n?-type drift layer 3 toward the cathode side (direction indicated by arrow) is measured by CV measurement. By this CV measurement, as depicted in FIG. 5, in the n?-type drift layer 3, at a position separated from the pn junction surface 12 between the p-type anode layer 4 and the n?-type drift layer 3 by the predetermined depth d11, a concentration compensated region 22′ of the n-type doping concentration by vanadium is detected.
