PURPOSE: To obtain peeling off resistance and corrosion resistance of a scratching off blade as well as its affluent toughness and wear resistance also by a method wherein an edge part of a blade is formed by a ceramic sintered body wherein an ion is implanted in its front face, rear face and side face.

CONSTITUTION: An edge part of a blade 1 is composed of a ceramics sintered body, and an ion 7 is implanted into a front face 4, a rear face 5, and both side faces 6 other than a contact face with a plate surface 2 of the edge part. Then, the ceramics should preferably be stabilized zirconia or alumina ceramics sheet (50μm) containing Y2O3 and MgO from a standpoint of high hardness, high strength, sheet workability, etc. However, when heat expansion, heat conductivity, etc., are regarded as important, alumina may be used. Energy to be implanted should be preferably from several tens kev to 1000kev, and an implantation quantity should be preferably 105-108 ion/cm2.