Process for producing plasma display panel

A method for producing a plasma display panel including a discharge space and a protective layer that faces the discharge space, wherein

• the protective layer includes a nano particle layer formed by nano crystal particles of metal oxides containing at least a first metal oxide and a second metal oxide;
• the nano particle layer has at least one peak in an X-ray diffraction analysis;
• the peak is located between a first peak in the X-ray diffraction analysis of the first metal oxide and a second peak in the X-ray diffraction analysis of the second metal oxide;
• the first peak and the second peak have the same plane orientation as the plane orientation indicated by the peak;
• the first metal oxide and the second metal oxide are two kinds of oxides selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide and barium oxide;
• the method comprising:
• exposing the protective layer to the reducing organic gas by introducing a gas containing a reducing organic gas into the discharge space;
• exhausting the reducing organic gas from the discharge space;
• and
• enclosing a discharge gas to the discharge space.