Patent ID: 7715022

Claim:
A shape measuring apparatus for measuring a shape of an edge of a thin sample comprising: first light emitting means for emitting light at sequentially different emitting angles to a measurement site which is an edge surface of the thin sample by lighting a light source at each of a plurality of positions in one plane; first light detecting means for, at a predetermined position, detecting a one-dimensional or two-dimensional luminance distribution of light emitted by the first light emitting means at each of the sequentially different emitting angles and reflected from the measurement site in an approximately specular direction; reflected light luminance obtaining means for obtaining a luminance distribution of the reflected light from the measurement site through the first light detecting means when light is emitted at each of the sequentially different emitting angles by the first light emitting means; and surface angle distribution calculating means for calculating a distribution of a surface angle of the measurement site based on luminance distributions of the reflected light obtained by the reflected light luminance obtaining means when light is emitted at the sequentially different emitting angles and the sequentially different emitting angles of the light emitted by the first light emitting means, wherein the surface angle distribution calculating means calculates a surface angle of the measurement site at each calculating object position in a light detecting range of the first light detecting means by performing a calculation for estimating an emitting angle of the light when luminance of the reflected light is peak, based on a relationship between each emitting angle of the light and luminance of the reflected light.