A mask container for storing a mask for photolithography, includes a cover and a base having a plurality of tapered corners. The tapered corners taper outward and downward from a top major surface of the base. The cover having the tapered corners extends downward that covers the tapered corners of the base when the cover is attached to the base. The tapered corners of the cover are tapered at about the same angle as the tapered corners of the base so that a surface of the tapered corners of the cover is substantially parallel to a corresponding surface of the tapered corner of the base when the cover is attached to the base. A recess is located in the tapered corners of the cover. A biasing member and a ball-shaped member are located in the tapered corners of the base to mate with the recess when the cover is attached to the base.