A plasma display panel that reduces a discharge voltage and increases discharge stability, includes: a rear substrate; a front substrate opposite the rear substrate; barrier ribs 130 disposed between the front substrate and the rear substrate and partitioning a plurality of discharge cells; pairs of sustain electrodes disposed on the front substrate, the sustain electrodes including bus electrodes and a plurality of projection electrodes electrically connected to the bus electrodes in each of discharge cells and projecting inwardly of the discharge cells; a front dielectric layer covering the sustain electrodes and having grooves therein corresponding to each of the discharge cells; address electrodes extending to cross the sustain electrodes and disposed on the rear substrate; a rear dielectric layer covering the address electrodes; phosphor layers disposed in the discharge cells; and a discharge gas in the discharge cells, wherein the length of the projection electrodes opposing inward the discharge cells is greater than the length of the grooves.