To provide a capacitor in which the operating characteristics of a semiconductor device can be ensured by ensuring the dielectric strength of a dielectric layer.

Both the lower electrode layer 2 and the upper electrode layer 4 constituting a capacitor 13 are composed not of a polysilicon based semiconductor requiring ion doping but of a metal not requiring ion doping. Contrary to a case where the upper electrode layer 4 is composed of a semiconductor, ion doping for forming a semiconductor is not required when the upper electrode layer 4 is formed and thereby structural defects, e.g. a pinhole, incident to ion doping can be eliminated from the dielectric layer 3. Since dielectric strength of the dielectric layer 3 is ensured, a defective display can be prevented from occurring in the display image of a liquid crystal display.