To provide a cooling device which can be constructed at a low cost and can prevent the generation of dew condensation in the cooling device for cooling an object to be treated with air.

The cooling device includes: a cooling chamber 10 in which the indoor air is used as a temperature-conditioning air that is temperature-conditioned; a conveyance conveyer 12 which carries-in an object to be treated 40 into the cooling chamber 10 and carries-out the object to be treated 40 from the cooling chamber to convey the object to be treated 40; a blower 14 which sucks and forcibly feeds the temperature-conditioning air in the cooling chamber; ducts 16b, 16c which guide the temperature-conditioning air, fed out by the blower 14, to the upper side and the lower side of the object to be treated, which is supported by a support means; and a blow-out box 22 in which the temperature-conditioning air guided by a guide means is blown to the object to be treated; wherein the temperature-conditioning air is blown to the object to be treated 40 from the upper side and the lower side at the same time to perform the cooling.