A mask frame assembly includes a frame having an opening, a support bar extended in a first direction crossing the opening of the frame and having distal ends installed over the frame, and a mask having extended in a second direction crossing the first direction, having distal ends installed over the frame, and having a pattern unit extended along the second direction and configured to pass a deposition material. The support bar includes a first opening disposed on one side of the support bar and having a first width in the second direction, and a second opening disposed on the other side of the support bar opposite to the one side of the support bar and having a second width greater than the first width in the second direction.