Using Eu2+ as the luminescence center for a green-emitting phosphor, a plasma display panel and a PDP device using it are configured by using an Eu2+-activated silicate green-emitting phosphate (Ca1-xM1x)2-e.M2.Si2O7:Eue with improved decay characteristics. In the formula, M1 is at least one element selected from the group containing Sr and Ba; M2 is at least one element selected from the group containing Mg and Zn; and x indicates the mole fraction of the component M1 and e indicates the mole fraction of Eu respectively satisfy the following conditions: 0