PURPOSE: To enhance durability and retain a clear stamp by constituting a stamping section of zirconia ceramic of high strength and high toughness.

CONSTITUTION: A stamping machine 10 consists of a projected stamping section main body 14 with a square section and a mounting flange 11, and the stamping section main body 14 and the flange 11 are manufactured integrally as a sintered material with PSZ(partly stibilized zirconia). A stamping surface 15 of the stamping machine 10 can be molded integrally at the time of molding, or stamped during the raw base state after molding, or else formed into the given stamped surface by supersonic processing using a whetstone as polishing powder after sintering. A recessed channel 16 having a shape corresponding to a JIS mark is formed on the stamping surface 15 of the stamping section main body 14, and also the corresponding shape can be raised as printing letters.