PURPOSE: To avoid the measuring with fault reflecting angle due to interference by providing means for supplying a laser beam, means for directing the beam, and means for detecting the angle of the reflected beam.

CONSTITUTION: The beams B1, B2 of monochromatic lasers L1 and L2 of wavelengths λ1, λ2 disposed at perpendicular axes are coupled by an optical element P to form a laser beam B1, which is incident on a sample S. A reflected beam BR. is sensed by a photodetector to decide the reflecting angle at the incident point of the beam B3. To measure a plurality of points on the surface of the sample S, when any one of the sample S, element P, lasers L1, L2 is moved, it functions as a scanning laser reflecting stress measuring apparatus. On the other hand, when the beam B3 is divided into a plurality of beams by the element P so that the beam B3 is incident on the plurality of points on the surface of the sample S, it functions as a beam split laser reflecting stress measuring apparatus.