Patent ID: 7095498

Claim:
A spectroscopic ellipsometer comprising: a lighting part for guiding polarized light to an object; and a light receiving part for receiving reflected light which is said polarized light reflected on said object to acquire a polarization state at each wavelength of said reflected light, wherein said lighting part comprises: a light source part; a polarizer which is a polarizing element for acquiring said polarized light from light outputted from said light source part; another light source part for emitting auxiliary light; an optical element for superimposing said auxiliary light on light from said light source part; and a light shielding pattern disposed at a position almost optically conjugate to an aperture stop position of an optical system from said light source part to said object on an optical path from said another light source part to said polarizer, said light receiving part comprises: an analyzer which is a polarizing element on which said reflected light is incident; a spectroscope on which said reflected light through said analyzer is incident; another optical element for extracting said auxiliary light from said reflected light; and an image pickup part disposed at a position optically conjugate to said light shielding pattern, for receiving said auxiliary light from said another optical element to acquire an image of said light shielding pattern, and said lighting part or said light receiving part comprises a rotation mechanism for rotating said polarizer or said analyzer.