Disclosed is a plasma display device that provides high luminance and minimal degradation in luminance under panel operations. A blue phosphor in a phosphor layer has a crystal structure of MeMgSi2O6:Eu or Me3MgSi2O8:Eu (where, Me contains at least one of Ca, Sr, and Ba) produced with a precursor that is obtained by any one of methods: an aqueous solution synthesis method, a spray synthesis method, a hydrothermal synthesis method, and a hydrolysis method. The phosphor has an average particle diameter ranging from 0.1 to 3.0 μm.