Patent attributes
When irradiating a sample with light from a light source through an object lens, discretely changing a relative position between a beam condensing position of the object lens and the sample in an optical axis direction of the converging beam, obtaining light intensity information from the sample at each relative position, extracting plural pieces of light intensity information from a light intensity information group, estimating a maximum value on a change curve adaptive to the plural pieces of extracted light intensity information and the relative position for the maximum value, and obtaining the estimated maximum value of the light intensity information and relative position as brightness information and height information, these information about the sample can be continuously obtained by discretely performing an iterative operation on the relative position between a beam condensing position of the object lens and the sample in an optical axis direction of the converging beam.