Abstract: After an interlayer insulator film is deposited on a wiring conductor formed on a semiconductor device element and is then planarized, a first conducting film and a first insulating film are deposited in the named order. Thereafter, a through hole is formed, and a second conducting film and a second insulating film are deposited and then etched back so that these films remain on only a side wall surface of the through hole. Furthermore, the through hole is filled with a metal plating, and then, the etching-back is performed again. Thereafter, an upper level wiring conductor is plating-grown by supplying an electric current to-the first conducting film , and the second conducting film remaining on the side wall surface and the lower level wiring conductor.