To provide a thin film deposition method capable of depositing a thin film with a desired film thickness distribution in a short time by using a mask with a simple opening shape, a mask used in the method, and a thin film deposition apparatus using the mask.

The mask has a plurality of divided apertures of the same shape to allow substances sputtered from an evaporation source to pass through. Since the apertures are divided into a plurality of ones, the area of each aperture can be reduced more, and the distribution of the substances passing through the apertures can be more uniform. Further, since the plurality of divided apertures are arrayed in a relative moving direction of a substrate, and a thin film of a desired film thickness distribution can be deposited without degrading the vapor deposition efficiency.