Patent ID: 7436516

Claim:
A reflection characteristic measuring apparatus, comprising: a light irradiating member for irradiating light toward a sample surface to be measured; a light detector, having a two-dimensional light receiving surface, for receiving reflection light from the sample surface illuminated with the light irradiated by the light irradiating member to output two-dimensional light receiving data concerning a first area corresponding to an area of the light receiving surface; an area setter for setting a second area at an appropriate position within the first area, the second area being smaller than the first area, to restrict light receiving data to be used in obtaining a reflection characteristic of the sample surface; and a calculator for obtaining a characteristic of the sample surface, based on two-dimensional light receiving data concerning the second area, wherein the area setter detects whether the two-dimensional light receiving data concerning the first area includes a peak value concerning light receiving, the area setter sets the second area, with a position of the peak value being defined as a reference position, if the peak value is detected, and the area setter sets the second area, with a central position on the first area being defined as the reference position, if the peak value is not detected.