PURPOSE: To stabilize running directionality and to facilitate the adjustment of a position, by a method wherein a disc is allowed to penetrate in parallel to a bonding part so as to grasp the bonding part and bonding is performed by utilizing the approach action of the surface to be bonded due to the deformation of a material.

CONSTITUTION: A material 209b cut so as to become slightly shorter than the peripheral length of a drum 201 is wound around the drum 201. The cut surfaces of the leading and rear ends thereof are opened and these parts are abutted each other by a splicing roller 205 to be spliced. The splice roller 205 is mounted to the drum so as to be inclined with respect to the axial core 245 thereof and pressed to the material 209b. When the drum 201 is rotated in this state, the material 209b is moved in the direction of the axial core 245 while guided by a rail 242 by the component force in the direction of the axial core 245 due to the inclination of the splice roller 205. The operation of bonding is performed from the center to one end part and, after the drum 201 and the splice roller 205 are returned to the center and the drum is rotated in the opposite direction, said operation is performed from the center to the other end part.