Patent attributes
According to the present invention, there is provided a security thread whose existence is not clarified, which is prevented beforehand from being removed, which can be attached even to a form of a commodity heretofore regarded as difficult, and whose use purpose range is enlarged, and the security thread can be constituted by a core member comprising a soft magnetic fiber (1) or the soft magnetic fiber and a core thread (4), and a cover member (2, 3) comprising a nonmetal material to cover the core member, constituted by covering the core member comprising the soft magnetic fiber or the soft magnetic fiber and core thread and a semi-hard magnetic material (10′) with the cover member, or constituted by covering the soft magnetic fiber or the core member comprising the soft magnetic fiber and a thermal welding thread (9) with the cover member.