According to one embodiment, a method for manufacturing a semiconductor device includes: forming an underlayer film that contains atoms selected from the group consisting of aluminum, boron and alkaline earth metal; and forming a silicon oxide film on the underlayer film by a CVD method or an ALD method by use of a silicon source containing at least one of an ethoxy group, a halogen group, an alkyl group and an amino group, or a silicon source of a siloxane system.