ALIGNER

PROBLEM TO BE SOLVED: To provide an aligner with which a reticle and a photosensitive substrate can be aligned in a highly precise manner, even when the fluctuation of magnification is generated on a reference member. SOLUTION: In an aligner provided at least with two alignment systems PAL and RAL, a reference member FBa, etc., has a reference plate FP and a relay lens system RL which are provided in a fixed manner inside a stage part ST. The reference plate has the first reference mark DX for the above- mentioned first alignment optical system, and the second reference mark LX for the second alignment optical system, the first and the second reference marks are vertical to the direction of measurement performed by the first and the second alignment optical system, and the reference plates has the symmetrical shape with reference to the prescribed block LL in the plane surface where the first and the second reference marks are formed.