A semiconductor device has an electrical fuse formed on a substrate, having a first interconnect, a second interconnect respectively formed in different layers, and a via provided in a layer between the first interconnect and the second interconnect, connected to one end of the second interconnect and connected also to the first interconnect; and a guard interconnect portion formed in the same layer with the second interconnect, so as to surround such one end of the second interconnect, wherein, in a plan view, the second interconnect is formed so as to extend from the other end towards such one end, and the guard interconnect portion is formed so as to surround such one end of the second interconnect in three directions, while placing such one end at the center thereof.