A front substrate contains a plurality of scan electrodes and sustain electrodes. Two strips of scan electrodes and two strips of sustain electrodes are alternately disposed on the substrate. In addition, a plurality of auxiliary scan electrodes is disposed on the front substrate so as to be parallel to the scan electrodes. On the back substrate, a plurality of priming electrodes is disposed parallel to the scan electrodes. Each auxiliary scan electrode has electrical connections to the scan electrode that performs scanning earlier than the scan electrode adjacent to each auxiliary scan electrode. With the structure above, a priming discharge occurs between the auxiliary scan electrodes and the priming electrodes.