Stage position measuring apparatus capable of restricting generation of temperature fluctuations to a measured value

摘要

A stage position measuring apparatus according to the present invention comprises a movable stage being mounted within a chamber, a system for optically measuring an position of the stage, a system for general air-conditioning of an atmosphere within the chamber, a system for locally air-conditioning an optical path of the measuring system, and a system for controlling the local air-conditioning system so that a temperature of an atmosphere in the optical path is substantially identical to that of an atmosphere around the optical path.