An optical alignment film and a liquid crystal thin film are adjacently formed. These films are irradiated with light. The optical alignment film is aligned, and the viscosity of the liquid crystal thin film is lowered becaus e of the increase of the temperature due to light irradiation. The liquid crystal molecules in the liquid crystal thin film are aligned similarly to t he alignment of the optical alignment film by use of the intermolecular force a t the interface between the optical alignment film and the liquid crystal thin film. The alignment of the liquid crystal molecules allows the recorded information to be held. While using this optical alignment film, a sufficiently large amount of signals are realized, and the thermal stability and the stability against light irradiation are ensured.