In the technology education of Japanese junior high schools there is a manufacturing activity where the students make something, like a bookshelf. The activity encompasses a variety of skills, for example, sawing and planing. It is difficult for the students to evaluate skills objectively by themselves in the manufacturing activities. This paper proposes a mechanism to support students with objectively evaluating skills of their own. The mechanism creates objective evaluations about the angle and the surface roughness of a workpiece by using the sensors of a mobile device. We proposed a mechanism Workpiece Evaluation Support Mechanism for Students, and confirmed that the mechanism is simple in terms of the displayed information and the number of steps.