PURPOSE: To provide a MIM type electron emitting element involving a small diode current and a high electron emitting efficiency.

CONSTITUTION: An electron emitting element 10 is equipped with a lower electrode 14 furnished on a glass base board 12 and an upper electrode 18 installed on the lower electrode 14 through an insulative film 16. The lower electrode 14 is made of an amorphous alloy consisting of Ta and Al. The insulative film 16 is prepared by subjecting the upper part of the layer of amorphous alloy, which is a material for the lower electrode 14 formed on the base board 12, to an anode oxidizing process, and has a uniform film quality free from grain boundary scattering. The upper electrode 18 is made of Al. When a high electric field is formed between the tower electrode 14 and upper electrode 18, the lower electrode 14 electrons near the Fermi level reach the upper electrode 18, and those electrons which have energy exceeding the vacuum level are released into the vacuum.