PURPOSE: To make the closure tightness of liquid crystal perfect by forming a liquid crystal layer, having neither a liquid crystal injection opening nor exhaust opening at any position of a substrate and spacer, by using a flexible plastic substrate which has a thin-film electrode on its surface.

CONSTITUTION: To obtain flexible plastic substrates 1 and 2, polyethylene terephtalate films, polybutylene terephtalate films, polyester sulfone films, or polycarbonate films are used and provided with transparent conductive film layers of an indium oxide and spacer 3 between substrates 1 and 2 should bond plastic substrates 1 and 2 tightly to form a liquid crystal layer made of liquid crystal substance 6 between substrates 1 and 2. Since none of substrates 1 and 2 and spacer 3 has a liquid crystal injection opening or exhaust opening provided, liquid crystal substance 6 is completely sealed and its closure tightness is never spoiled during the use.