A mask includes a first mask that includes a first long side that extends in a first direction and a first short side that extends in a second direction that crosses the first direction and that includes a first edge portion, a first center portion, and a first welded portion, that are sequentially arranged in the first direction. The mask further includes a second mask that includes a second long side that extends in the first direction and a second short side that extends in the second direction and that includes a second welded portion, a second center portion, and a second edge portion, that are sequentially arranged in the first direction. The first welded portion is in contact with the second welded portion.