Intervals of the frame portion and the p type guard ring on a cell portion side are made narrower than other parts, and the narrowed part provides a dot line portion. By narrowing the intervals of the frame portion and the p type guard ring on the cell portion side, the electric field concentration is reduced on the cell portion side, and the equipotential line directs to more outer circumferential side. By providing the dot line portions, the difference in the formation areas of the trench per unit area in the cell portion, the connection portion and the guard ring portion is reduced, and the thicknesses of the p type layers formed on the cell portion, the connection portion and the guard ring portion are uniformed. Thereby, when etching-back the p type layer, the p type layer is prevented from remaining as a residue in the guard ring portion.