a method of manufacturing a semiconductor device provided with a first insulating film and a barrier film on a conductive region and an opening portion in the first insulating film and the barrier film , the method comprising the steps of : forming a first opening portion in the barrier film reaching the first insulating film ; forming a second insulating film at least on the first insulating film in the first opening portion ; and forming a second opening portion smaller than the first opening portion and reaching the conductive region by simultaneously boring a hole into the first insulating film and the second insulating film in the first opening portion .