PURPOSE: To make warming up for a long time unnecessary by a method where-in uniform heating over all peripheral surfaces is enabled to be carried out even for a thick thickness work, a broad width work, and complicated sectional form work.

CONSTITUTION: In a continuously carried hot blast vulcanizer wherein a plurality of slit nozzles are provided to an upper side of a work A and its lower side, the upper and lower slit nozzles are provided mutually reversely aslant to a carrying direction N-N of the work A so that hot blast 10a from the upper side slit nozzle intersects hot blast 10b from the lower side slit nozzle. The hot blast from one side slit nozzle makes the other side hot blast stay thereby to raise temperature of an atmosphere surrounding the work A.