A method for manufacturing a mask includes providing a mask mother substrate including a first portion and a plurality of second portions adjacent to the first portion, forming a reflecting plate on the mask mother substrate, forming a photoresist layer on the reflecting plate, removing a third portion of the photoresist layer that overlaps the plurality of second portions using an auxiliary mask, removing a fourth portion of the reflecting plate that overlaps the plurality of second portions, and removing the plurality of second portions of the mask mother substrate using a laser.