A method of forming a storage capacitor in an IPS liquid crystal display device
is proposed, and a technique of forming a pixel region having a high aperture ratio
is provided. An anodic oxidation process at an applied voltage/voltage supply time
ratio of 11 V/min is performed for insulating films used in each circuit of an
electro-optical device, typically an IPS method LCD, in particular for the surface
of a common electrode formed on a resin film. The amount of formation of the extra
anodic oxide film can be reduced by covering with an anodic oxide film, and a liquid
crystal display device with high reliability and having an electrode with superior
adhesion can be manufactured.