To provide a base board cooling device capable of increasing the cooling speed of the base board.

The base board cooling device for cooling the base board G, treated by heating on a heat resistant setter S, is provided with a perforated plate 21 for sending out air upwardly against the lower center of a cooling chamber while a plurality of slit nozzles 22 for sending out air upwardly are arranged so as to be aligned at a place except the perforated plate 21. The central part of the base board G can be cooled with the same speed or more quickly compared with the cooling speed of an outer peripheral part so as to obtain a temperature distribution wherein the base board G is hardly broken and, further, the base board G is cooled indirectly from the lower part thereof through the setter S whereby the base board G can be cooled in a high speed without generating any warpage.