Abstract: A system for measuring topological features, such curvatures and profiles, of surfaces such as semiconductor wafer surfaces. The system includes a) laser means and lens means for directing a beam of weakly-convergent light for incidence on a surface which is to be measured, b) photodetector means for detecting the position of the laser light beam reflected from the surface, c) first translation means for providing relative movement between the laser means and the surface in a direction which is normal to the direction of the incident beam, so that the incident beam is caused to scan across the surface, e) position sensing means connected to the photodetector means for detecting the location on the photodetector means at which the reflected beam is incident.