An apparatus for deflecting light of the present invention comprises: (a) at least one pair of transference electrodes arranged facing one another; (b) a drive circuit which applies a voltage among the transference electrodes; and (c) a liquid crystal which is inserted among the transference electrodes, and whose parallel stripes that function as a diffraction grating when the voltage is applied among the transference electrodes are produced at a pitch corresponding to the applied voltage. The light can be scanned if a diffracted light by the apparatus for deflecting light is converted into a scanning light and a voltage value is changed temporally to apply the voltage among the transference electrodes. In a device for reading information, the scanning light is reflected in a bar code and the reflected light is detected by an apparatus for detecting light. In a device for stereoscopic display of the present invention, the apparatus for deflecting light is used as beam deflection means for deflecting the light beamed from a picture element which organizes the pictures of the picture display means.