PURPOSE: To obtain a low-cost front glass panel of a high flatness by composing it of low cost glass of soda lime silica composition only, and performing an ion exchange between ions in fused salt and ions in glass to change an image displaying glass part to be of anti-electron beam browning glass.

CONSTITUTION: The titled device consists of an image displaying glass part 2 where electron beams are radiated, and side wall glass parts 3, and the glass composing the image displaying glass part 2 is made to be a plate of anti- electron beam browning glass of soda lime silica composition having a surface layer to which an ion exchange is applied for ions in glass in fused salt including at least one sort of ions among potassium, sodium and lithium. The glass composing the side wall parts 3 is a glass plate of soda lime silica glass composition, and the glass of the image displaying part 2 is connected or heat welded with the glass parts of the side wall parts 3 by low fusing point glass frits 4. The front glass panel including the image displaying surface of a light-weight, low cost, good precision and high flatness can thus be obtained.