This invention provides an exposure mask including a translucent film formed on a light-transmitting substrate and having a mask pattern, and a stabilized region formed in the boundary between the light-transmitting substrate and the translucent film or on at least the surface of the translucent film to prevent variations in physical properties of the translucent film. In addition, this invention provides a method of manufacturing an exposure mask, including the steps of forming a translucent film on a light-transmitting substrate, forming a photosensitive resin film on the translucent film, forming a photosensitive resin pattern by exposing the photosensitive resin film to a radiation or a charged particle beam, removing an exposed portion of the translucent film by using the photosensitive resin pattern as a mask, removing the photosensitive resin pattern, and forming a stabilized region in the boundary between the light-transmitting substrate and the translucent film or on at least the surface of the translucent film before the step of forming the photosensitive resin film or after the step of forming the photosensitive resin pattern. Also, this invention provides an apparatus for manufacturing an exposure mask, including a light source for radiating light containing at least an exposure wavelength onto a translucent film formed on a light-transmitting substrate, a photodetecting unit for detecting light emitted from the light source and transmitted through or reflected by the translucent film, and a measuring unit for measuring the characteristic of the translucent film from the light detected by the photodetecting unit.