An optical position detecting apparatus detects a position level and inclination of a surface of an object to be detected without the need to increase the working distance of an objective optical system. The apparatus includes an objective optical system having a lens arranged to face the surface, an illuminating optical system for supplying a position detecting light beam from the periphery of the objective optical system, a photodetector for generating an electric output corresponding to a light beam received, a condenser optical system for converging a reflected light beam from the surface illumunated with the incident light beam from the illuminating optical system onto a photosensing surface of the photodetector, and a beam directing optical element for directing at least one of the incident light beam and the reflected light beam into an optical path passing through the lens.