Disclosed are a driving device and a driving method for a plasma display panel (PDP). A panel capacitor is formed by a scan electrode and a sustain electrode. The charges are moved from the panel capacitor to a capacitor by turning on a transistor which is connected between the scan electrode and the capacitor. By this method, the voltage of the panel capacitor is steeply reduced so that a discharge is generated in the panel capacitor. When the voltage of the capacitor increases because of the charges moved from the panel capacitor, the gate-source voltage of the transistor is reduced. As a result, the transistor is turned off so that the scan electrode is floated. Accordingly, the discharge is steeply quenched so that the wall charges are precisely controlled. After the capacitor is discharged, the above-noted operation may be repeated.