The present invention provides a plasma display panel (PDP) with a protective film improved so as to achieve a lower discharge starting voltage. A surface portion of the protective film 16 substantially is composed of magnesium (Mg), aluminum (Al), nitrogen (N), and oxygen (O). The protective film 16 is formed so that in the surface portion of the protective film 16, a ratio of the number of atoms of the aluminum to a total of the number of atoms of the magnesium and the number of atoms of the aluminum is at least 2.1% but not more than 66.5%, a ratio of the number of atoms of the nitrogen to a total of the number of atoms of the nitrogen and the number of atoms of the oxygen is at least 1.2% but not more than 17.2%, and a ratio of the total of the number of atoms of the nitrogen and the number of atoms of the oxygen to the total of the number of atoms of the magnesium and the number of atoms of the aluminum is at least 1.0 but not more than 1.35.