To achieve the shortening of a cooling time and the shortening of a process, and to reduce the production cost of a liquid food by installing a device obtained by integrating a detachable stirrer and a cooler in a standard vessel having a deep depth and used for the production, and continuously bringing the liquid current of the liquid food into contact with the cooler to cool the liquid food.

The liquid food 2 is cooled by installing a device obtained by integrating the detachable stirrer 4 and the cooler 6 in the vessel 1 for storing the liquid food 2, and continuously bringing the liquid current of the liquid food 2 into contact with the cooler 6 by the stirrer 4 to cool the liquid food 2.