Disclosed herein is a semiconductor device including: an insulating film configured to be provided on a substrate and be porosified through decomposition and removal of a pore-forming material; a covering insulating film configured to be provided on the insulating film; and conductive layer patterns configured to be provided in the covering insulating film and the insulating film and reach the substrate, wherein the insulating film includes a non-porous region in which the pore-forming material remains.