In a PDP apparatus a first protrusion is formed in the column direction at a scan electrode. A second protrusion is formed in the column direction at a sustain electrode. The first and second protrusions face each other with a protrusion gap therebetween. An area of the first protrusion is greater than that of the second protrusion. A first sustain pulse is applied to the scan electrode and a second sustain pulse is applied to the sustain electrode in a sustain interval. In an exemplary embodiment a first interval during which a voltage of the first sustain pulse is less than that of the second sustain pulse is longer than a second interval during which a voltage of the first sustain pulse is greater than that of the second sustain pulse.