In the present invention, a non-contact type probe (PRB) capable of measuring simultaneously distances to three points on a model surface is used to determine inclination increments in the X and Y directions from the distances of the points A, B and C with respect to the probe that are measured at each predetermined sampling time, and calculate the normal direction N of the model at the measuring point A. An increment of each axis per sampling time is determined from (i) the increment of each of the three axes of rotation of the orthogonal coordinates system and the two axes of rotation of the probe necessary for turning the optical axis (OPI) to the normal direction while the measuring point A is kept fixed and (ii) a feed quantity per each sampling time and the distances measured by distance measuring means. While the optical axis (OPI) is directed to the model normal direction by performing simultaneous 5-axis control using these increments, the model (MDL) is profiled.