To control, in joining a raw tire base body and a tread ring, the air pool, biting of the outer edge of the tread ring, and the like.

The equipment is for forming a raw tire 4 by making a raw tire base body 2 held by a former 10 and a tread ring 3 that is waiting in its outside in the radial direction bond together concurrently with the inflation of the raw tire base body 2 by the expansion of a rubber bladder 12. The rubber bladder 12 is equipped with ring-like both ends 31 fixed to clamps 14 of the former 10 and an expansible body 30 of a cylindrical form extending between them. In the outer end marginal region 30E of the body 30, an expansion controlling layer 32 is formed which controls the expansion of the outer end marginal region 30E when the body 30 expands.