A semiconductor device 1 includes a base body 3 that includes a p type substrate 4 and an n type semiconductor layer 5 formed on the p type substrate 4 and includes an element region 2 having a transistor 40 with the n type semiconductor layer as a drain, a p type element isolation region 7 that is formed in a surface layer portion of the base body such as to demarcate the element region, and a conductive wiring 25 that is disposed on a peripheral edge portion of the element region and is electrically connected to the n type semiconductor layer. The transistor includes an n+ type drain contact region 14 that is formed in a surface layer portion of the n type semiconductor layer in the peripheral edge portion of the element region. The conductive wiring is disposed such as to cover at least a portion of an element termination region 30 between the n+ type drain contact region and the p type element isolation region.