PURPOSE: To increase the writing speed by holding the thin layer of a liq. crystal substance contg. a smectic liq. crystal and a cholesteric liq. crystal represented by a specified structural formula as principal components between two confronting substrates each provided with an electrode.

CONSTITUTION: The thin layer 6 of the liq. crystal substance is held between a glass substrate 1 provided with a transparent indium oxide electrode 2 and a glass substrate 3 provided with an Al electrode 4 and with a Cd-Te layer 5 under the electrode 4, and the layer 6 is sealed with an epoxy resin adhesive 7. The liq. crystal substance contains a smectic liq. crystal such as n-octylcyanobiphenyl, and the thickness of the thin layer 6 is 7.5μm. The surfaces of the two substrates and the two electrodes contacting with the liq. crystal substance are oriented parallel by diagonally vapor-depositing silicon oxide.