A flat panel display device includes a first substrate; an electron emission region formed on the first substrate; a second substrate located at a predetermined distance facing the first substrate and forming a vacuum vessel with the first substrate; and a light emitting region which emits light derived by electrons emitted from the electron emission source. The light emitting region includes an anode in a predetermined pattern that formed on the second substrate and a phosphor screen layered on the anode. A proportion, k between a screen weight of the phosphor screen and an average diameter of phosphor particles on the phosphor screen satisfies: k=S/(Dn) where, k ranges from 0.16 to 0.23, S is the screen weight (mg/cm.sup.2), D is the average diameter of the phosphor particles, and n is the number of accumulation layers of the phosphor powder particles on the phosphor screen.