A method of manufacturing a liquid crystal display device which includes pixel electrodes and common electrodes which are alternatively arranged in each pixel defined on a substrate, including the steps of: forming a conductive film on the substrate; forming a mask layer, of which etching selection ratio is different from the conductive layer, on the conductive layer; forming a photo-resist pattern of a fixed pattern on the mask layer; forming a mask pattern, which has an undercut shape to the photo-resist pattern, by etching the mask layer by use of the photo-resist pattern as an etching mask; removing the photo-resist pattern; and etching the conductive film by use of the mask pattern as an etching mask, to provide at least any one of the common electrode and the pixel electrode.