Collector mirror exchanging apparatus and method for extreme ultraviolet light source apparatus

An extreme ultra violet light source apparatus for generating extreme ultra violet light by irradiating a target material in a chamber with a laser beam from outside of said chamber to generate plasma and collecting a predetermined wavelength component emitted from the plasma, said apparatus comprising:

• a collector mirror configured to reflect and collect a predetermined wavelength component emitted from plasma generated within the chamber;
• a cooling unit provided at a rear side of said collector mirror and including pipes formed of a flexible material, and configured to circulate a coolant;
• a position adjusting stage configured to adjust a position and/or a posture of at least said collector mirror, said position adjusting stage includes at least one of an XYZ stage movable in three-dimensional directions, a stage rotatable in a horizontal plane, and a stage rotatable in a direction of elevation angles;
• a guide rail configured to regulate a moving direction of at least said collector mirror on a supporting base within said chamber, said guide rail being arranged not to cross a plane, the plane being perpendicular to an axis and passing through a plasma generation point within the chamber, the axis including the plasma generating point and a focusing point of extreme ultra violet light reflected by said collector mirror, and the guide rail is arranged such that the moving direction of the collector mirror on the supporting base is parallel to the axis which includes the plasma generating point and the focusing point;
• and
• an alignment member fixed on the supporting base and aligning a position of at least said collector mirror on the supporting base.