Patent ID: 7081946

Claim:
A mask holding method for holding a mask in which a surface to be attracted has a convex shape towards a first direction within a predetermined allowable range, with a pair of first attraction holding sections arranged opposing the first direction, wherein the mask is held so as to satisfy the following relational expression: δ< Pl 1 2 (2 l 1 +3 l 2 )/6 EI where l 1 respectively denotes an interval between a central supporting point and an outside supporting point of the mask in the respective first attraction holding sections, l 2 denotes an interval between the central supporting points in the respective first attraction holding sections, δ denotes an interval between the outside supporting point and the mask, which is generated when the mask is mounted on the central supporting point, P denotes a product of the atmospheric pressure and an attraction area of the first attraction holding section, E denotes a modulus of longitudinal elasticity of the mask, and I denotes a geometrical moment of inertia of the mask.