To easily form a conductive film consisting of a metallic oxide excellent in equality of film thickness by applying organic metallic compound solution not less than the fusing point and not more than the resolution temperature, and then, baking it at the resolution temperature or over.

Element electrodes 4 and 5 are made on an insulating substrate 1 by a vacuum deposition method or a lift-off method, and thereon the pattern of a Cr film 7 is made. This substrate 1 is heated to not less than the fusing point of the organic metallic compound of center metal such as Pd, etc., and not more than the resolution temperature, using an infrared ray lamp 4, etc. Hereon, the above organic metallic compound solution is applied to form the film 11. Next, these are put in an oven 12, and are baked at the resolution temperature or over to form a conductive film 13 consisting of metallic oxides such as PdO, etc. Then, the Cr film 7 is removed, and voltage is applied to partially break or transform or transmute it so as to form an electrically highly resistant electron emitting part, thus an electron emitting element with little dispersion of electron emitting property is obtained.