The present invention provides a plasma display panel that suppresses
discharge sustain voltage, and reduces brightness degradation of a
phosphor. In the plasma display panel, as protective film (14) made of
magnesium oxide (MgO) formed on dielectric glass layer (13), protective
film (14) made of magnesium oxide (MgO) with oxide added with an
electronegativity of 1.4 or higher, is formed to suppress impure gas
adsorption by protective film (14), stabilizes discharge sustain voltage,
and reduces brightness degradation.