1. A distance measuring system for measuring a distance between two spots on a wafer, comprising: a microscope to produce a picture of a predetermined view-field displaying a predetermined region of the wafer; and a control device, wherein the control device calculates: standard coordinates of respective standard points in respective view-fields that each include one of the two spots with respect to a basis point of the wafer; spot coordinates of the two spots, respectively, with respect to the respective standard points; real coordinates of the two spots, respectively, from the respective standard coordinates and the spot coordinates; and the distance between the two spots from the real spot coordinates.