A surface position detecting apparatus according to an aspect of the present invention has a light-sending optical system which makes first light and second light from first and second patterns incident at different incidence angles to a predetermined surface to project an intermediate image of the first pattern and an intermediate image of the second pattern onto the predetermined surface; a light-receiving optical system which guides the first light and the second light reflected by the predetermined surface, to a first observation surface and to a second observation surface, respectively, to form an observation image of the first pattern and an observation image of the second pattern on the first and second observation surfaces; and a detecting section which detects a piece of position information of the observation image of the first pattern and a piece of position information of the observation image of the second pattern and calculates a surface position of the predetermined surface, based on the pieces of position information. The light-sending optical system has a sending-side reflecting section which reflects the second light having passed via sending-side common optical members, an even number of times to make the second light incident at the incidence angle smaller than that of the first light to the predetermined surface.