FILM THICKNESS MEASURING INSTRUMENT

摘要

PROBLEM TO BE SOLVED: To provide a film thickness measuring instrument which prevents a sample for correction from having secular changes. SOLUTION: The film thickness measuring instrument which measures the thickness of a thin film on the surface 8a of a sample according to measurement information on the quantity of polarization variation has a reloading stage 7 for the sample or the sample 21 for correction arranged nearby the stage 7 and is also equipped with a gas supply means 24 which purges the atmosphere around the sample surface with inert gas.