The aim of the invention is to provide boxes for keys that can be produced at low costs, especially when they form an integral part of a series of boxes of different capacities. For this purpose, the housing of such a box is configured with side walls (7, 8) screwed together with an upper part (1) and a lower part (2) and a back wall (22 22) guided in a guide groove (18, 19) of the side walls (7, 8). The side walls (7, 8) and the door (13) of the housing are preferably constituted of continuous profiled elements cut to shape and the back wall (22, 22) as well as the upper and lower parts (1, 2) consist of diecast elements. The back wall is provided with perforations (24) for hanging at least one key rail (25).