PURPOSE: To obtain a grinded ceramics surface of slight roughness in the grinding of ceramics surface with a lapping machine, by altering a ceramics surface to be processed to a easily removable material with a tribochemical reaction, and removing simultaneously the altered layer until no layer remains on the processed surface.

CONSTITUTION: A surface of a ceramics is grinded with a composite lapping machine composed of oxide grinder grains or reducing grinder grains altering the surface to be processed of a ceramics of high hardness to an easily removable material and mechanically removing grinder grains somewhat harder than the altered layer such as alumina, then the altered layer on the processed surface produced by a tribochemical reaction can be removed so as that no altered layer remains on the processed surface of the ceramics to complete the mirror grinding of the surface.