To perform a high current density operation by using an Al alloy for a lower electrode and improving electro-migration and stress migration resistance in a thin-film electron source.

An Al-Nb alloy film is formed on an insulating substrate 10, and film thickness is set according to the request specification of wiring resistance required for a lower electrode 11. The surface of this lower electrode 11 is anodic-oxidized, and next only the side surface of the lower electrode 11 is selectively and thickly anodic-oxidized. Next, an upper electrode 13 is formed as a three-layer film. Because a little amount of Nb to be added of an alloy material contains in the insulating layer 12 formed by anodic-oxidizing the surface of the Al-Nb alloy, degradation of an insulating characteristics is small. Nb is oxidized simultaneously with Al by an anodic oxidation and becomes an insulating material, degradation of the insulating characteristics is further smaller. Therefore, leak current is reduced and a high efficient electron emission similarly as when Al is used for the lower electrode 11 can be realized.