A ferroelectric memory device has a lower insulating film formed on a semiconductor substrate. A ferroelectric capacitor structure is formed on the lower insulating film. The ferroelectric capacitor structure is created by layering in order a lower electrode, ferroelectric layer and upper electrode. The ferroelectric memory device also has an upper insulating film which covers the ferroelectric capacitor structure. A wiring layer is formed over the upper insulating film. An aluminum oxide film of thickness 5 to 50 nm is formed so as to cover the wiring layer and upper insulating film.