A laser beam is scanned on an object surface with a fast scanning system which consists of a rotating mirror, a flat mirror, and a concave spherical mirror. Propagation direction of the laser beam reflected by a sample surface is detected with a lens and a position sensitive detector. A one-dimensional surface profile of the sample surface is measured by integrating a slop distribution obtained from the propagation direction of the reflected beam. The measurement is insensitivity to mechanical vibrations because of a high-speed scanning of a few milliseconds. The required positioning accuracy of the sample surface is lower than a few millimeters. The measurement repeatability is less than 10 nm.