METHOD AND APPARATUS FOR DETECTING SOLID SHAPE AND METHOD AND APPARATUS FOR INSPECTION

PROBLEM TO BE SOLVED: To inspect the solid shape of an object under inspection with high accuracy and at high speed. SOLUTION: A slit light illuminates an object 1 under inspection through an objective 15, a reflected light from the irradiated region is reflected by a perforated mirror 14 and branched by beam splitters 18a, 18b on three optical paths, after passing through an aperture restriction 16 and an image-forming lens 17. Line sensors 7a, 7b are provided for each branch optical path, the line sensor 7a is disposed in front of the focal plane, the line sensor 7b is disposed behind the focal plane, the line sensors 7a, 7b are positionally adjusted so that n-th detection pixels of the sensors 7a, 7b receive the image of n-th unit regions on the slit light irradiated region of the object 1, the defocus quantity of the images on the planes of the light sensors 7a, 7b differs, depending on the unit region height on the slit light irradiated region of the object 1 and cells of the light sensors 7a, 7b detect the light quantity, corresponding to the defocus quantity.