To reduce the aging effect of electron emission efficiency during driving even when a glass substrate containing a component other than SiO2 is used by generating a cover layer mainly made of SiO2 on a no-alkali glass base to obtain a substrate forming an electron emitting element.

A no-alkali glass base 1, which has the content of an alkaline metal except for quartz glass preferably 0.1% or below and has small electric conductivity in the movement of alkaline metal ions, is used, and a cover layer 6 mainly made of SiO2 is formed on its surface by the vacuum deposition method or sputtering method. The alkaline metal content in the cover layer 6 is set to 1/10 or below of the alkaline metal content in the no-alkali glass. The material of opposite element electrodes 2, 3 is selected from a transparent conductor or a semiconductor material such as polysilicone. An electron emission section 5 is constituted with a gap formed at part of a conductive film 4 made of the step coverage between the element electrodes 2, 3 or the resistance value between the element electrodes 2, 3 in a forming process.