Abstract: A method of measuring the profile of a three-dimensional object including the steps of scanning the surface of the object to be measured with a slit-ray, forming an optical image of the surface of the object on an imaging plane of a nonscanning type two-dimensional image sensor which is composed of a plurality of mutually independent photosensors, measuring each time interval between a time when the slit-ray passes a predetermined point and a time when reflected rays are received by any of each of the plurality of mutually independent photosensors, storing each of the time intervals measured in separate memory means with a one to one correspondence between the position of each of the plurality of photosensors and each of the plurality of separate memory means and determining the profile from the time interval stored.