PURPOSE: To remarkably improve the productivity of a second-stage forming apparatus per unit time without shortening an operation cycle forcibly, by constituting the apparatus so that a plurality of second green tires can be formed simultaneously.

CONSTITUTION: A servicer 50 being moved to the right, a belt material B thereon is wound round on a blet-tread assembly forming drum 30. Next, the serivcer 50 being moved to the left, a tread material T is supplied onto the belt wound round on the forming drum 30. Then the forming drum 30 is rotated to form a belt-tread assembly. Each assembly thus formed is removed from the forming drum 30 by each of transfer devices 20 and is transferred thereby in the direction of former rings 10. In the meantime, an operator moves to the former rings 10 and forms a first green tire on each of the former rings 10. The belt-tread assembly each transferred by said transfer device 20 is stuck on this tire and fitted thereon completely by a tread stitcher 60.