Abstract: An object of the present invention is to provide a liquid crystal display device such as an FLC display which is significantly reduced for the temperature dependence of the liquid crystal properties. A liquid crystal optical device 31 in which a plurality of transparent substrates 2a, 2b are opposed to each other at a predetermined gap 32, with transparent electrodes 3a, 3b and liquid crystal alignment films 4a, 4b being disposed, respectively, to the opposing surfaces and ferroelectric liquid crystal (FLC) 30 is disposed in the gap 32, wherein the ferroelectric liquid crystal 30 has a layer texture 30A, and the change of the layer tilt angle is less than 3.degree. within an entire temperature range in the smectic C* phase.