To enable the reduction of the space required for arrangement of a cooling system, by bringing, recovery air into contact with a cooling medium under different environments thereby performing cooling and dehumidification separately in plural stages, and further, defrosting a cooling coil without using a defrost device.

This system is arranged such that the upstream side in the direction of the air circulation of the preliminary cooling part 4A of a chill generation room turns several times in zigzag, and cooling fin coils 8A as heat exchangers where brine circulates are arranged to stand in the direction of air circulation. Then, recovery air is brought into contact with a cooling medium with a preliminary cooling part 4A to perform preliminary cooling and preliminary dehumidification, and then, the cooling and dehumidification are performed on a full scale with the body cooler 4B on the downstream side of the preliminary cooling part 4A, thus the processing is performed separately in plural stages. Moreover, the frost adhering to the cooling fin 8A is defrosted, and it is drained out of a chill generation room from a discharge port 17A.