Abstract: Disclosed is a semiconductor device. The semiconductor device includes a lower electrode disposed on a substrate; a first lower interfacial film disposed on the lower electrode; a dielectric film disposed on the first lower interfacial film; a first upper interfacial film disposed on the dielectric film; and an upper electrode disposed on the first upper interfacial film, wherein each of the first lower interfacial film and the first upper interfacial film is a conductive single film, and the first lower interfacial film and the first upper interfacial film include the same metal element, wherein electronegativity of the metal element included in each of the first lower interfacial film and the first upper interfacial film is greater than electronegativity of a metal element included in the dielectric film.