PURPOSE: To supply a carcass readily by hunging it and to improve handleability by imparting a toroidal shape to a carcass layer, and vertically providing a second state manufacturing device wherein a breaker tread structure is assembled.

CONSTITUTION: When the breaker tread structure is assembled on a drum device 1 of a third stage manufacturing device C, a shaft is protruded and aligned with the center of a conveying ring D2 of a conveying device D, and the tread structure is delivered to the conveying ring D2. During this period, a ring 31 of a carcass supplying device E rotates and lowers the carcass layer being sent by a conveying device F to the central position of the shaft over a second stage manufacturing device A, and the carcass layer is placed on a bead ring of the drum device of the device A. Then the outer diameter of the third stage manufacturing device C, which has delivered the structure to the conveying ring D2, is expanded, and a worker performs assembling work of the breaker tread structure of the following tire.