FIG. 4 is a diagram schematically depicting measured depths (CV measured depths) of doping concentrations. FIG. 4 depicts an example in which no n-type buffer layer is provided. Reference numeral 11′ is an interface between the n-type starting substrate 1 and the n?-type drift layer 3. In FIG. 4, parts identical to those in FIG. 1 are given the same reference numerals used in FIG. 1. FIG. 5 is a characteristics diagram depicting depth distribution of the n-type doping concentration of the n?-type drift layer measured by CV measurement. In FIG. 5, depth [μm] in the n?-type drift layer 3 from the pn junction surface 12 between the p-type anode layer 4 and the n?-type drift layer 3 (=0 μm) toward the n-type cathode layer (the n-type starting substrate 1) is shown on a horizontal axis. Further, in FIG. 5, the n-type doping concentration [/cm3] of the n?-type drift layer 3 is shown on a vertical axis.
