Machine inspection refers to the inspection of machine parts and operating mechanisms. This includes a wide range of precision measurements and inspections in each process at production sites, operational precision measurements and inspections of operating mechanisms, and precision measurements and inspections in temperature-controlled rooms. These common knowledge and skills are tested in the skills test. There are special grades and grades 1 to 3. Special grades are the level of skills that managers or supervisors should normally have, and grades 1 to 3 are usually for advanced, intermediate, and elementary technicians, respectively. It is positioned as the degree of skill that should be possessed.