PURPOSE: To eliminat the difference of partial refractive index and reflectivity and to prevent color shading and lowering of contrast, by providing a thin film which consists of an insulating material having the same thermal coefficient of expansion as transparent electrodes further at the inner side of flexible polymer film substrates.

CONSTITUTION: A common electrode 3 and a segment electrode 4 are provided with transparent conductive films such as indium oxide and tin oxide etc. at the inner side surfaces of the upper and lower substrates 1, 2 of flexible polymer films. These electrodes 3, 4 are arranged so as to be connected with an outside circuit through a lead electrode 5 and so that an electric field is applied. A thin film 6 which consists of an insulating material having almost the same thermal coefficient of expansion as that of the electrodes 3W5 is provided allover the surface at the substrates 1. 2. As such a thin film 6, e.g. TiO2 film, SiO2 film and Al2O3 film are used. Even if about 150°C thermal stress is applied in a calcining process of manufacturing process of a liquid crystal display device, the generation of strain is prevented by an action of the thin film. The warpage of of polymer film substrates is eliminated and the gap between both substrates are kept uniform.