A semiconductor device includes an electric fuse formed on a semiconductor substrate and composed of an electric conductor. The electric fuse includes an upper layer interconnect, a via coupled to the upper interconnect and a lower layer interconnect coupled to the via, which are formed in different layers, respectively, in a condition before cutting the electric fuse, and wherein the electric fuse includes a flowing-out region formed of the electric conductor being flowed toward outside from the second interconnect and a void region formed between the first interconnect and the via or in the via, in a condition after cutting the electric fuse.