A cathode is formed on a glass substrate by depositing nickel thereon, and silicon dioxide is allowed to accumulate on the cathode by sputtering to form an insulator film. Then, a gate electrode is provided on the insulator film by depositing nickel thereon. A hole is formed on the glass substrate by lithography to carry out patterning, and the gate electrode and the insulator film are selectively etched to create a hole for the formation of an emitter emitting electrons. Furthermore, nickel is stacked into the hole by deposition to form the emitter, and subsequently the emitter is covered with sulfur as a high vapor-pressure substance to form a high vapor-pressure substance layer.