A reticle stage reference mark 3 of material having high reflectivity to alignment illumination light is provided on a reticle 5, and a chuck mark 8 of material having high reflectivity to the alignment illumination light is provided on a wafer chuck 11. A relative position of the reticle stage reference mark 3 to the chuck mark 8 is detected by using a first position detection optical system 1 and a first illumination optical system 2, and relative alignment is performed between the reticle 5 and a wafer 10.