a semiconductor device includes grooves defining an active region , including a misfet , and dummy regions . a first interlayer insulation film is formed over the misfet , the active region and the dummy regions . a first wiring , and first and second dummy wirings are formed over the first interlayer insulation film . a second interlayer insulation film is formed over the first wiring and the dummy wirings . the second dummy wirings are arranged between the first wiring and the first dummy wirings , and the pitch of the first dummy wirings is larger than that of the second dummy wirings . in planar view , the first and second dummy wirings are arranged over the dummy regions , and the size of each of the first dummy wirings is larger than size of each of the second dummy wirings . the first wiring and the first and second dummy wirings are formed of copper as a major component .