To provide a profile measuring method by sequential three-point method capable of measuring a profile of micro-size machine elements, and its system concerning a small engine lather capable of machining and profile measuring of the micro-size machine elements and to measure the profile by a three-point method by suppressing interference of displacement meter.

A measuring object 59 and three laser displacement meters 89, 91 and 93 arranged around the measuring object 59 are supported relatively-rotatably around the axis of the measuring object 59. A computer 109 is provided for individually detecting in turn the surface displacement of the measuring object 59 with each laser displacement meter 89, 91 and 93 by the relative rotation of the measuring object 59 to the three laser displacement meters 89, 91 and 93. The computer 109 calculates the profile of the object 59 by synthesizing the detection results of each laser displacement meter 89, 91 and 93.