PURPOSE: To obtain a silicon oxide film having a thin thickness formed on a storage electrode when forming a capacitor insulating film and improve characteristics of the capacitor insulating film, by forming the storage electrode with a boron doped P-type polysilicon film.

CONSTITUTION: The present invention comprises the steps of forming a polysilicon film 29 serving as a storage electrode of a capacitor on a semiconductor substrate 21, forming the polysilicon film 29 as a boron doped P-type polysilicon film, and forming a capacitor insulating film 30 and further a plate electrode 31 on the storage electrode 29 made of the P-type polysilicon film. Accordingly, by forming the storage electrode of the capacitor with the boron doped P-type polysilicon film 29, a silicon oxide film having a thin thickness formed on the storage electrode 29 can be obtained and the characteristic deterioration of the capacitor insulating film 30 can be reduced.