Abstract: A surface examining method and a surface examining apparatus, in which a large-sized lens of an object-side telecentric optical system is not required and which can observe a surface to be examined in a wide region. A surface examining method for examining a surface of an object to be measured, by observing a light reflected from the object through an object-side telecentric optical system or an image-object-side telecentric optical system, comprises the steps of; arranging the object-side telecentric optical system or the image-object-side telecentric optical system so that an optical axis thereof is inclined with respect to a direction normal to the object to be measured, and observing the light reflected from the object to be measured.

Abstract: The present invention provides a light illuminating method, a surface examining method using the light illuminating method, and apparatuses for performing these methods. In the surface illuminating apparatus for illuminating an object with a light beam from a light source through a lens member for illumination, the lens member for illumination has a characteristics with respect to a longitudinal aberration caused by a spherical aberration in the light source side of the lens for illumination, that an amount of shift from a paraxial image surface to image formation points gradually increase or decrease, with an increase in height of light incidence into the lens; and the light source is set at a position in an outside of a group of the image formation points.

Abstract: A method enables measurement of the configuration of a pattern with irregularity in a wide surface region with a high accuracy and in a single operation. The surface inspecting method includes irradiating a measurement objective region with an illuminating light in an oblique direction thereto; forming an image of reflected light from the measurement objective region, the formed image of reflected light having points with luminance corresponding to the incident angle of the illuminating light at respective points on the measurement objective region picking up the formed image to collect luminance data of respective points in the measurement objective region; analyzing spatial frequencies of the luminance data with respect to positions in a desired direction to make a plurality of spatial frequency data; and extracting a desired frequency component from the plurality of spatial frequency data.