To provide a hot blast heating type heat treatment system which can improve the temperature distribution property within a heating chamber, and shorten the processing time, and prevent the breakdown of plate-shaped substance to be processed, and reduce cost, and improve clearness, without complicating the operation or the structure.

A heat treatment device 2 generates hot blast to heat plural sheets of plate-shaped substance 3 supported by a rack 15 within a heating chamber 13, and reciprocates the rack 15 between the heating chamber 13 and a cooling chamber 14, and has an opening/closing mechanism for the connection port 12a between the heating chamber 13 and the cooling chamber 14. It is provided with a dustproof filter which passes the hot blast. The plate-shaped substance 3 to be processed supported, in the cooling chamber, by the rack 15 is capable of heat radiation, and besides, it is equipped with a means for compulsively cooling the plate-shaped substance to be processed.