Workpiece position detection system

PROBLEM TO BE SOLVED: To provide a work position detection system capable of detecting a stable position of a work which is a transparent body.SOLUTION: A system comprises: at least one light projecting part (21a-21c) for irradiating a work which is transparent with light to cause an end surface of the work to emit light; imaging parts (22a and 22b) for imaging a light emitting location caused by the light on the end surface of the work; and a detecting part for detecting a work position on the basis of imaging result by the imaging part.