To provide a position detecting apparatus that executes high-accuracy overlapping while ensuring throughput.

The position detecting apparatus includes a substrate stage on which a substrate formed with a mark is loaded, an optical detection means for optically detecting a position of the mark, a stage position measuring means for measuring a position of the substrate stage, a measurement-condition determining means, which determines any one or more measurement conditions of the number of times of optical detection for optically detecting the position of the mark corresponding to the position of the substrate stage, accumulated time of the optical detection of the position of the mark, and the number of times of measurement of the position of the substrate stage, and a control part that exerts control so as to execute optical detection of the position of the mark by the optical detection means corresponding to the measurement conditions.