A filing device which can detachably secure and hold sheet-like materials to be filed at the inner side of the spine with reliable adhesion without forming punching holes in which non-staining soft polyurethane elastomer having continuous high adhesion at room temperature is secured to the inner side of the spine and the sheet-like materials are secured to and held with the polyurethane elastomer at their edges, and also supplemental sheet-like materials to be used with said filing device.