To provide a cooling method by which many small bag packages can be efficiently cooled at once without attachment of water on the surfaces, thereby without staining the surface of the small bag packages (the surface of film) by cooling water, and further to provide a cooling apparatus having a simple structure and capable of being readily treated, at cheap cost.

This cooling method comprises storing small bag packages in a bag body 12 having an air-sucking valve formed at a required position, and an opening part with an opening and closing means at one side, hermetically sealing the bag body 12 storing the small bag packages, sucking the air from the hermetically sealed bag body 12, supplying the air-sucked bag body 12 in a liquid 16a for cooling to cool the small bag packages. The cooling apparatus has a means for storing the small bag packages in the bag body 12 having the air-sucking valve formed at the required position, and the opening part with the opening and closing means at one side, an air-sucking means for sucking the air in the hermetically sealed bag body 12, and a cooling means by the liquid for the cooling, for cooling the air-sucked bag body 12.