Method for manufacturing a semiconductor device including a semiconductor substrate, an element formed on the substrate, and an insulating film formed on the element, includes: (a) forming a first conductive layer (b) forming a first insulating film on the upper portion of the first conductive layer; (c) forming a second insulating film with a porous structure on the first insulating film; (d) forming a third insulating film different from the second insulating film on the second insulating film; (e) forming a via hole in the second and third insulating film by dry etching of the third insulating films; (f) removing a part of the first insulating film such that the surface of the first conductive layer is exposed at the bottom of the via hole and (g) forming a second conductive material film layer so as to fill the via hole.