A semiconductor device is disclosed which includes active section 100, edge termination section 110 having a voltage blocking structure and disposed around active section 100, and separation section 120 having a device separation structure and disposed around edge termination section 110. A surface device structure is formed on the first major surface of active section 100, trench 23 is formed in separation section 120 from the second major surface side, and p+-type separation region 24 is formed on the side wall of trench 23 such that p+-type separation region 24 is in contact with p-type channel stopper region 21 formed in the surface portion on the first major surface side and p-type collector layer 9 formed in the surface portion on the second major surface side. The semiconductor device and the method for manufacturing the semiconductor device according to the invention facilitate preventing the reverse blocking voltage from decreasing and shorten the manufacturing time of the semiconductor device.