The termination region includes a ring region (LNFLR). A plurality of ring-shaped P-type ring layers are regularly arranged in the ring region (LNFLR). The ring region (LNFLR) is divided into a plurality of units which include the plurality of P-type ring layers respectively. A width of each unit is constant. A total number of P-type impurities in the ring region (LNFLR) is N, the target withstand voltage is BV [V], a width of each unit is SandL [μm], and the number of the plurality of units is num, following relationships are satisfied. N≧(M×BV)γ, M=104 to 105, γ=0.55 to 1.95, SandL×num×Ecri≧2×α×BV, Ecri=2.0 to 3.0×105 [V/cm], α=100 to 101. Widths of the P-type ring layers of the plurality of units linearly decrease toward an outside of the termination region.