A plane display includes a plurality of pixel capacitors, each of which includes first and second electrodes and a non-linear optical material disposed therebetween. A plurality of storage capacitors are respectively provided in association with the plurality of pixel capacitors, each of which includes the first electrode of the corresponding pixel capacitor, an insulating film, and a third electrode insulated from the first electrode through the insulating film and connected to an external power supply terminal. Additionally, a provided for each storage capacitor and connected between the third electrode of the associated storage capacitor and the external power supply terminal, for preventing a potential drop causable in the course of storing electric charge in the associated storage capacitor.