PURPOSE: To stabilize electron emission properties for a long duration under high current density by forming an intermediate layer containing a specified amount of nickel particles and scandium oxide between an electron emitting substance layer and a substrate.

CONSTITUTION: An intermediate layer 2a is formed between an electron radiating substance layer 2 and a substrate 1. The intermediate layer 2a contains 5-20wt.% of nickel particles, oxides of alkaline earth metals including barium, and 0.1-20wt.% of scandium oxide. Composite oxide formation in the periphery area of in the interface of the substrate 1 is thus suppressed. Consequently electron emitting properties can be stabilized for a long duration even under high electric current density and a long life at high electric current is achieved.