To provide a high-accuracy optical surface even if a point of inflection is on a worked surface of a workpiece, or even if there are plural points of inflection thereon.

According to this curved surface cutting method, a rotating tool 8 is relatively moved to a work 1 having a projecting or recessed point 12 of inflection 12 on a work curved surface 1a to cut the work curved surface 1a. In the method, the feed speed of the work 1 or the tools 8, 10 in moving during the cutting work is made different between the longitudinal surface containing the point 12 of inflection of the work curved surface 1a and a continuous surface connected to the longitudinal surface, so that it is decreased on the longitudinal surface to be worked.