In a center mechanism of a tire vulcanizer of the present invention, in order to improve working efficiency and lower total height, after a green tire is vulcanized and patterned and becomes a vulcanized tire, a bladder well is lifted from a bottom position where a lower bead ring is positioned on a lower mold and a bladder is installed in the green tire to a top position where the lower bead ring is positioned above the lower mold and an upper clamp, and the upper clamp, a lower clamp, and the bladder are placed in the bladder well, while heights of the upper clamp and the lower clamp are fixed.