PURPOSE: To eliminate difference in the shapes of an electrode by removing the insulating layer around the side of the cop part of an annular or a recessed emitter electrode provided on the bottom of a small hole, by isotropic dry etching, and by forming the emitter electrode relatively easily without contraction controlling the diameter of the opening part of the small hole.

CONSTITUTION: A photoresist mask pattern 13 is formed on an insulating Si substrate 10 having a conductive layer 10a. An emitter electrode layer 15 is formed by sputtering Mo. An outer tilted surface 15a is formed on an electrode layer 15 formed on the outer periphery of the side wall of the cylindrical mask pattern layer 13, by anisotropic etching. Etching removal is also conducted from the layer 10a to another electrode layer 15 excluding the outer tilted surface 15a. The mask pattern 13 is removed by plasma etching, and a space part 15b is formed in the layer 15. An emitter electrode 17 having a pointed annular front end part 16 is provided on the top part of the layer 15. An insulated layer (SiO2 layer) 11 surrounding an electrode 17 is formed, and a gate electrode (Cr) layer 12 is formed thereon, to form a small hole 14 by the layers 11, 12.