GLASS SUBSTRATE HOLDING MEANS AND METHOD FOR MANUFACTURING EUV MASK BLANK USING THE SAME

PROBLEM TO BE SOLVED: To provide glass substrate holding means capable of suppressing generation of a flaw in a glass substrate and adhesion of an extraneous material on the glass substrate due to holding without causing displacement and detachment of an EUV mask glass substrate and deformation of the glass substrate.SOLUTION: Holding means 100A for a glass substrate 200 has an electrostatic chuck mechanism attracting the rear face of the glass substrate in a noncontact manner and a support member 114 for supporting a part of the rear face of the glass substrate. The ratio of a projected area (mm) of an action surface 112 exhibiting electrostatic attraction force of an electrostatic chuck to an area (mm) of a quality assurance region 210 of the rear face of the glass substrate (the projected area of the action surface of the electrostatic chuck mechanism/the area of the quality assurance region of the rear face of the glass substrate) is equal to or more than 0.5. A distance between the action surface 112 of the electrostatic chuck mechanism and the rear face of the glass substrate 200 is more than 20 μm. The glass substrate holding means holds only a region including at least two sides among four sides configuring the support member 114 which is outside the quality assurance region 210 of the rear face (rear face periphery) of the glass substrate 200.