AF/RSNOM is a new kind of scanning probe microscope developed in our lab, which is a combination of atomic force microscope and reflection scanning near field optical microscopy (AF/RSNOM) working in equi-amplitude tapping mode. This paper introduces the principle of AF/RSNOM and its advantages compared with other reflection mode scanning optical microscopes (RSNOM). Compared with the former RSNOM, this tapping mode AF/RSNOM has convenient operation and fewer background signals.