There are provided a sample cooling device capable of effectively removing moisture in the air inside an accommodating chamber where a sample container is accommodated, and of preventing a problem caused by occurrence of frost, an autosampler provided with the same, and a sample cooling method. A first driving process of setting a set temperature of a dehumidifier section to at or below the freezing point, and a second driving process of stopping driving of the dehumidifier section or of raising the set temperature of the dehumidifier section to above the freezing point after the first driving process is performed over a predetermined period of time are performed. Thus, the set temperature of the dehumidifier section may be made to at or below the freezing point by the first driving process, and moisture in the air inside the accommodating chamber may be made to temporarily attach to the dehumidifier section as frost and then be melted by the second driving process and be collected as water.