To provide a shape measurement method capable of executing exact shape measurement surely detecting abnormal data regardless of the degree of the shape error concerning an object to be measured without erroneously detecting normal data as abnormal data or detecting abnormal data as normal data.

The shape measurement method has a process for obtaining a measurement data by scanning the object to be measured, calculating approximate measurement shape from the measured data, and deleting or correcting points parting from the approximate measurement shape more than a predetermined abnormal data threshold to obtain corrected measurement data 19. The corrected measurement data 19 is transformed in a process into a coordinate system indicating the design type data 10 of the object to be measured. In another process, the shape error of the object to be measured is obtained with the corrected measurement data 19 and the design type data 10.