To provide a technique capable of positioning parts put near to an X-ray generating part by using a low-cost apparatus with respect to an aligner with an X-ray exposure light beam.

In a aligner, an X-ray light source 3 for generating an X-ray beam by making a material in a plasma state is provided. The X-ray beam from the X-ray light source 3 is used as an exposure light beam. The aligner includes light-source position observing systems 21X and 21Y for forming an image of the X-ray light source 3 when visual light is cast along with the X-ray beam from the X-ray light source 3. In the aligner in which an X-ray beam from the plasma, especially a laser-plasma X-ray beam, is used as a light source, the position of the part is reproduced with high accuracy even when the parts around the light source is replaced.