A plasma display panel (PDP) includes front plate, scan electrodes and sustain electrodes both formed on front plate, dielectric layer covering scan and sustain electrodes, and protective layer formed on dielectric layer. Protective layer contains silicon (Si) and nitrogen (N), and is made of magnesium oxide (MgO) including Si of which atoms count in the range from 5.times.10.sup.18 pieces/cm.sup.3 to 8.times.10.sup.21 pieces/cm.sup.3. The foregoing construction allows the PDP to shorten a discharge-delay time, achieve a quick response of discharge to a voltage applied, and suppress changes of the discharge-delay time with respect to a temperature.