A plasma display apparatus is disclosed. The plasma display apparatus includes a plasma display panel including a first electrode and a second electrode connected to a reference voltage source, a negative voltage controller that supplies a negative voltage output from a negative constant voltage source to the first electrode, a sustain driver, and a negative voltage blocking unit. The sustain driver supplies a sustain signal to the first electrode, and one terminal of the sustain driver is connected to one terminal of the negative voltage controller. The negative voltage blocking unit prevents the negative voltage from being supplied to the reference voltage source through the sustain driver while the negative voltage controller supplies the negative voltage to the first electrode.