Rubber label

The label (2) has a magnetic layer (4) containing magnetically conductive substances. The magnetic layer is covered by a barrier layer (6). The label is detachably arranged on a mold surface of a side wall shell of a vulcanizing mold by magnetic force so that the label is fixed on the mold surface in a position by fixing devices during molding a green tire. The fixing devices are arranged at the side wall shell. The label is vulcanized on a side wall of a tire during a vulcanization process. The label is detachable from the mold surface.