PURPOSE: To achieve an appropriate vulcanization without causing any damage to the surface of a work, by doing the vulcanizing operation in such a manner as to supply a vulcanizing chamber, in which a vulcanizable elastomer good it set, with mixture fluid of a gas of high pressure and low heat capacity and a heating fluid of high heat capacity.

CONSTITUTION: A vulcanizing chamber, which is composed of a top metallic mold 2, a bottom metallic mold 3 and a bladder 1, is filled with a vulcanizable elastomer article A, and a prescribed vulcanizing condition is incorporated into a controlling meter 8 having a built-in microcomputer. And then, automatic regulating valves V1 and V2 are opened and V3 is closed, a gas G of high pressure and low heat capacity is introduced into a mixer 5 from an inlet 11, a heating fluid S of low pressure and high heat capacity is sucked in from a suction hole 12 by pressure of the gas to be mixed with the gas, the mixture is supplied to the bladder 1 from a discharging hole 13, and while detecting pressure and temperature by a pressure signal emitter 6 and a temperature sensor 7, the elastomer good A is vulcanized.