THREE-DIMENSIONAL SHAPE MEASURING DEVICE

PURPOSE:To provide a device having high precision and high reliability by detecting the focal point position with a laser interferometer, and obtaining the inclination at the focal point position with a position detecting element. CONSTITUTION:The light transmitting a beam splitter 2, a polarization beam splitter 4, and a 1/4-wavelength plate 5 in sequence is condensed on a measured object 7. The reflected light from the measured object 7 is reflected on the polarization beam splitter 4 and fed to a half-mirror 12. Part of the light from the measured object 7 transmitting the half-mirror 12 is fed to a position detecting element 13, and the inclination at the focal point position on the measured object 7 is measured from the position of the incident light. A signal processing device 11 determines the shape of the measured object 7, and the three-dimensional shape of the measured object 7 is determined with higher precision from the inclination at the focal point position on the measured object 7 outputted from the position detecting element 13.