A method for manufacturing small magnetic disks from a nonmagnetic large disk. A nonmagnetic large disk is first prepared, and subjected to at least one step of a manufacturing process necessary for manufacturing a magnetic disk from a nonmagnetic substrate. The manufacturing process may comprise the steps of applying at least one underlayer to the substrate, applying the layer of magnetic material to the underlayer, applying the protective layer to the layer of magnetic material, applying the lubricating layer to the protective layer, carrying out a texture treatment, polishing the underlayer, and burnishing the protective layer, and carrying out a levitation and characteristic test. After at least one of these steps, the large disk is divided into a plurality of the small disks. Accordingly, it is possible to manufacture small magnetic disks, by the use of manufacturing equipment designed to manufacture large magnetic disks.