A tire vulcanizer is provided which is capable of arranging a sector at a specified position during closing of a mold and suppressing a vulcanization molding defect. The tire vulcanizer includes: the sector that shapes a tread of a tire; paired upper and lower side plates that shape sidewalls of the tire; a segment to which the sector is fixed and which causes the sector to move in a tire radial direction; and mold parting surfaces defined by the sector and the side plates. Mold inner ends of the mold parting surfaces are arranged on the tread, and the mold parting surfaces extend outward in the tire radial direction from the mold inner ends. The sector includes paired upper and lower flange sections which respectively abut the paired upper and lower side plates in a state where the adjacent sectors in the tire circumferential direction tightly contact each other.