A plasma display panel includes display cells disposed in matrix at cross
points of a plurality of common electrodes and a plurality of data
electrodes. In each of the display cells, data writing discharge and
sustaining discharge are performed to emit light. Brightness is controlled
by applying a sustaining pulse having a frequency higher than .mu..sub.i
V/(.pi.d.sup.2) between the sustaining electrodes, where .mu..sub.i is an
ion mobility of the discharge gas filled in the display cell, V is a
maximum value of the applied voltage, and d is a distance between the
sustaining electrodes performing the sustaining discharge.
