PURPOSE: To obtain a long-life panel by providing a maintaining electrode on the side surface of a barrier rib, and generating a discharge in the parallel direction with a front surface substrate and a rear surface substrate on which fluorescent films are arranged to prevent the deterioration of a fluorescent body due to discharge impact.

CONSTITUTION: A writing electrode 2 is provided on a front surface substrate 1 and a barrier rib 5 is provided on a rear surface substrate 4 and a maintaining electrode 6 is provided on both side surfaces thereof. A fluorescent film 3, 8 is provided on the substrate 1, 4. A voltage inverted in phase is applied between the electrodes 6. When a higher voltage than a discharge initiating voltage is applied to the electrode 2, a discharge is generated between the electrode 2 and the electrode 6 and the discharge makes a trigger to generate a discharge between these two electrodes 6. Ultraviolet rays are generated in the selected cell, so that a fluorescent film 3, 8 on the substrate 1, 4 is excited to emit light. Since the electrode 6 is provide on the side surface of the barrier rib 5, the discharge is generated in the parallel direction with the fluorescent film 3, 8, so that the deterioration of the fluorescent body due to discharge impact may be prevented to gain a long-life panel.