A vulcanizing method including a cylindrical vulcanizing drum for winding and molding unvulcanized rubber belt materials thereover, the vulcanizing drum being removably and rotatably supported on a transfer mechanism. A pair of endless pressurizing bands are arranged to oppose each other with the vulcanizing drum between, the pressurizing bands arcuately surrounding and pressing the corresponding portions of the circumferential surface of the vulcanizing drum. While the circumferential surface of the vulcanizing drum is heated inside, and the respective pressurizing bands are opposingly pressed against the vulcanizing drum, the respective pressurizing bands are synchronously rotated so as to turn the vulcanizing drum and continuously vulcanize the unvulcanized rubber belt molding on the drum.