The mechanical properties of thin films sputtered onto glass substrates using an in-line sputtering system were investigated. The internal stress in the films was found not to be isotropic: the component of compressive stress parallel to the substrate conveyer direction was higher than that perpendicular to the substrate conveyer direction. The adhesion strength of the films measured by the scratch test was smaller when scratched parallel to the conveyer direction than scratched perpendicularly. Consequently, the film was not degraded uniformly by the Taber abrasion test. In contrast. the component of tensile stress parallel to the substrate conveyer direction was smaller than that perpendicular to the substrate conveyer direction. The parallel component of compressive stress was reduced when films were deposited in multiple pass mode. Such anisotropy may be ascribed to the oblique incidence of the sputtered particles when the substrate entered and left the coating zone of the target.