A reflection characteristic measuring apparatus includes: 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. The area setter detects whether the
two-dimensional light receiving data concerning the first area includes a
peak value concerning light receiving; sets the second area, with a
position of the peak value being defined as a reference position, if the
peak value is detected; and 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.