| 摘要 |
PURPOSE:To measure intervals of edges of a pattern having an optional angle, by providing a rotating means or the like which rotates a scanning track and an object to be measured relatively so that the scanning track of a spot light crosses deges of the pattern to be measured at a prescribed angle. CONSTITUTION:An edge detector is provided with a reflective mirror 5, an image rotating prism 6, etc. to which the light beam reflected by the reflective mirror 5 is made incident. This detector is provided with a rotating means 60 which rotates the scanning track and the object to be measured relatively so that the scanning track of the spot light crosses the edge of the pattern to be measured at a prescribed angle. In this case, the rotating means 60 is so constituted that it rotates the image rotating prism 6 around an optical axis Cl in the direction of an arrow W. Thus, intervals of edges of the pattern having an optional angle are measured. |
