To provide a dielectric capacitor which exhibits proper electrical characteristics by preventing the advancing diffusion of an external substance, such as a reducing element or the like to a dielectric film, and to provide a method for manufacturing the same.

According to a ferroelectric capacitor C103, the advancing diffusion of a hydrogen generated, when an oxide film 7 and an oxide film 9 are formed to a ferroelectric film 7 is prevented by a first hydrogen diffusion preventing film 101. Further, since the sidewall of a ferroelectric film 4 is covered with a second hydrogen diffusion preventing film 102, advancing of the hydrogen from this sidewall to the film 4 is completely prevented. Accordingly, electrical characteristics of the film 4 is held proper. Since the film 102 does not exist on the upper surface of the film 7, the height of the capacitor C103 is suppressed to a necessary minimum limit. This acts advantageously, with respect to planarization of the entire semiconductor device formed with the capacitor C103.