To suppress a vulcanizing trouble from developing due to the air accumulation between a bead core and the turned up part of a carcass layer.

In a bladder, which is constituted by arranging rubber layers 12 and 13 inside and outside a reinforcing layer 11, bent flat to the inner diameter side at the end part of a forming drum at an un-inflated state and inflated from the forming drum to its outer diameter side at inflated state so as to turn up the end part of a carcass layer about a bead core, the rigidities of the rubber layers 11 and 12 at a bent pat 1B opposite to the drum side are made higher than those of the rubber layers 12 and 13 at a bent part 1B on the drum side.