A semiconductor device includes a capacitor which has: a lower electrode formed along an opening provided above a semiconductor substrate to have a concave cross section; a capacitor insulating film formed on the inner and top surfaces of the lower electrode; and an upper electrode formed on the capacitor insulating film. The upper electrode includes: a first conductive film formed on the inner surface of the capacitor insulating film and filling the opening; and a second conductive film formed to extend from the top surface of the first conductive film to the top surface of the capacitor insulating film.