Atomic force microscopes (AFMs) can be used to observe microwear processes and to evaluate microwear properties of solid surfaces. This is important in developing the very small and lightweight mechanical devices now beginning to be used. A very sharp diamond tip is used for scratching. There are two types of microwear process. One involves only surface depression, and the other forms upheavals on a scratched surface as a pre-stage of wear. There are two types of upheaval. One is caused by plastic deformation, and the other is caused by the production of chemical compounds by reaction with environmental gas molecules. Microwear tests using an AFM have just started. Wear tests on silicon and C+-implanted silicon showed that the wear durability of the C+-implanted silicon around the maximum C+ ion concentration was higher than that of the silicon.