Abstract: A container for storing a plurality of semiconductor wafers comprises two end walls and two side walls. The container has a main opening through which the wafers are inserted into or withdrawn from the container and a sub-opening through which a wafer counter approaches the wafers. A plurality of slots are formed in the container to hold the wafers one by one at intervals. Each slot includes a pair of grooves which are formed in inner surfaces of both the side walls, have a V-shaped cross-section, and which divergently open toward a central portion of the container. One surface of each groove serves as a supporting surface on which a wafer is disposed substantially horizontal when the container is positioned such that the reference plane is horizontal. The supporting surfaces of the pair of grooves have a pair of converging portions which converge toward the second opening.