PURPOSE: To obtain a high quality product having a uniform cooling temp. distribution by dividing plural nozzles arranged around a heated product into some groups and regulating the amount of gas jetted from the nozzles every group.

CONSTITUTION: Plural nozzles 15 are arranged around a place 10 for setting a heated product 11 and cooling gas is jetted toward the place 10. The nozzles 15 are divided into plural groups and the amount of the cooling gas jetted from the nozzles 15 is regulated every group with regulating means 21 so as to obtain a cooling temp. distribution necessary for the product 11.