A surveying instrument comprises a projection optical system for irradiating a distance measuring light which is a linearly-polarized light to an object to be measured, a light receiving optical system for receiving a reflected distance measuring light from the object to be measured, a polarization selecting module for selecting a polarization of the reflected distance measuring light received by the light receiving optical system and an arithmetic control module for controlling a distance measurement based on a light receiving result of the reflected distance measuring light, wherein the arithmetic control module is configured to give a material information to a distance measurement result of the object to be measured based on a change in light receiving amounts caused due to a selection of the polarization by the polarization selecting module.