COLD CATHODE ELECTRON SOURCE

PROBLEM TO BE SOLVED: To provide a diamond cold cathode electron source possible to be easily made two-dimensional and operable at a low voltage. SOLUTION: A striped cathode electrode 3, a polycrystalline diamond thin film 4 and a striped gate electrode 5 are formed one by one on an insulating substrate 2. The cathode electrode 3 is disposed perpendicularly to the gate electrode 5. A hole 7 having a bottom in contact with the surface of the diamond thin film 4 is provided in the crossing area of the cathode electrode 3 and the gate electrode 5. If a voltage is applied to the cathode electrode 3 and the gate electrode 5, an electron 10 by an electric field is emitted from a part where the hole exists, on the surface of the diamond thin film 4 in their crossing area, and this structure can be operated as a two dimensional cold cathode electron source.