On the outer surface of the glass face panel 2 of a display device, a first layer 5 of an electrically conductive transparent thin film, a second layer 6 of another transparent thin film consisting essentially of silicon dioxide (SiO₂) or magnesium fluoride (MgF₂), and a third layer 7 of uneven exposed surface, are deposited, whereby a multiplicity of concave regions of said third layer 7 form an interference film together with said first 5 and second layer 6, whereas a multiplicity of convex regions of said third layer form an irregular reflection surface.