In the initializing period of each of sub-fields comprising one field, one of all-cell initializing operation and selective initializing operation is performed. The all-cell initializing operation causes initializing discharge in all the discharge cells for displaying an image. The selective initializing operation selectively causes initializing discharge only in the discharge cells subjected to sustaining discharge in the preceding sub-field. During initializing discharge using scan electrodes as anodes, and using sustain electrodes and data electrodes as cathodes in the all-cell initializing period, applying, to the data electrodes, a voltage for delaying discharge using the data electrodes as the cathodes, after discharge using the sustain electrodes as the cathodes.