PURPOSE: To eliminate a problem about the corrosion of glass frit caused by sodium solution eluted due to leak current and humidity, and prevent the deterioration thereof and the break of an image display element, regarding a front vessel of soda lime silica glass used for the image display element.

CONSTITUTION: A teflon coat layer 7 is formed on the outer side of a front vessel 1, thereby restraining a flow leak current from the vessel 1 to glass frit 6 and a rear vessel 5, and the supply of electrons. As a result, the reduction of sodium ions is prevented and the moisture proof effect of the layer 7 also restrains the generation of alkaline solution. In addition, the corrosion of the glass frit 6 is prevented. An image display element of high reliability can be thereby provided.