A tread mold includes a securable region at an outer circumferential portion thereof which is capable of being secured to a jig at a machining apparatus, and a positioning surface at the outer circumferential portion thereof which is capable of making surface contact with a reference surface at the jig so as to permit positioning to be carried out relative to the jig, the positioning surface is arranged so as to face in the tire circumferential direction so as to permit the tread mold to be positioned relative to the jig in the tire circumferential direction.