A mask frame assembly for depositing a deposition material on a deposition substrate comprises a mask frame including an opening and frames surrounding the opening, and a mask coupled on the mask frame. A deformation prevention unit is formed on at least one region of the mask. Since the deformation prevention unit is formed on a peripheral portion of a deposition pattern in the mask, deformation of the mask in a vertical direction may be reduced. Accordingly, defective attaching of the mask to the substrate may be reduced.