To make it possible to control the state of a liquid crystal having excellent orientation with light by irradiating a liquid crystal cell with light in the state applying a bias electric field to cause an orientation change.

The oriented state of a liquid crystal in the nematic liquid crystal cell arranging a polyimido oriented film on it is controlled with light. A liquid crystal cell with e.g. a 2μm gap is made, and a liquid crystal is enclosed into it, and when an electric field is applied to it, the orientation is changed according to whether or not the electric field applied to the cell exceeds a threshold value, and though light transmission is switched according to this change, this matter doesn't mean that the orientation of the liquid crystal is changed by the light irradiation. On the contrary, when the electric field slightly smaller than the threshold is applied, and the light irradiation is performed, e.g. when E=2.5V, a light intensity 0.6mW/cm2; 36°C, the transmission light intensity is reduced according to the light irradiation, and the switching is caused by the light. When the light irradiation is stopped, the transmission light intensity is returned to the origin, and the transmission light intensity is reduced again by the light irradiation, and the switching is induced repeatedly.