To reduce tire noises by forming at least a tread center section on the outer surface of a tread section into a cylindrical face having the same distance from a tire rotary shaft at the time of vulcanization.

The radial direction outer ends of side wall sections 14 extended to the nearly radial direction outside from a pair of bead sections 13 are connected together to form the nearly cylindrical tread section 15 of a tire 11. A cylindrical face 46 having the same radius at any position is provided at least at a width direction center section within a tread die face kept in contact with the outer surface of the tread section 15 of an unvulcanized tire on the inner face of the sector mold of a vulcanizing die for vulcanization molding. The cylindrical face 46 having the same distance from a tire rotary shaft at any axial direction position at the portion kept in contact with the cylindrical face 46 is provided within the tread section 15 of the unvulcanized tire at the time of vulcanization. The width W of the cylindrical face 46 is preferably set to 0.05 times a tread ground width S or above.