In a former half (T11) of an all-cell reset period (T1), the potential of a scan electrode (Scn) is raised from 0 [V] to Vp [V] at a timing t0, and thereafter maintained at the positive potential of Vp [V] to Vg [V] until a timing t3 when the former half (T11) ends. On the other hand, in the same former half (T11), a reset pulse (Pul.2), which includes a negative ramp waveform portion from 0 [V] to a potential of Vr [V], is applied to a sustain electrode (Sus). A time period (t1−t0) of the negative ramp waveform portion of the pulse (Pul.2) is set longer than a time period required for the potential change of a pulse (Pul.1) from P1 to P2.