PROBLEM TO BE SOLVED: To provide an atomically sharp edge cutting blade for a cutting device. SOLUTION: A novel cutting edge is formed by evaporating a coating to the cutting blade edge of a cutting blade blank and processing with a focused ion beam. When the coating 6 is applied to one side only, as a surplus coating material 6 is usually evaporated on abase bottom 11 in the coating process, the surplus coating material is removed. After that, the blank 5 is sharpened by the focused ion beam (FIB) process, and a sharp edge (cutting blade edge) 9 with an atomically sharp edge cutting blade is produced. As for a both-side inclined cutting tool in which both sides of the blank are tapered and coated with a hard material, each coating surface of the blank is mulled with the focused ion beam (FIB) and a novel sharp edge part with an atomically sharp both-side inclined blade edge is produced.