The teaching tool in which metal surface analyzed image was developed. The teaching tool has been composed of lens and charge-coupled device camera, two light-emitting diodes. The teaching tool expands the metallic surface, and it is compared with the surface roughness specimens. The curriculum which utilized the teaching tool in the class of junior high school industrial arts and homemaking course manual training course was examined. As a result of utilizing the teaching tool, the quality of student works have been remarkably improved and the expansive learning on the surface finishing became possible.