To completely sterilize the interior of a freezer itself even without the necessity to disassemble and clean it, by providing a sterilization function on the freezer.

A means to supply a sterilizing water is provided on an atomizing nozzle 3, and the sterilizing water is supplied to the atomizing nozzle 3 in such a state that a fan 2 is driven and is sprayed. The fine particles of the sterilizing water which are discharged from the atomizing nozzle 3 are thoroughly spread through the entire interior of a freezer 4 by the fan 2 for stirring so that bacteria present even in the minute parts of the freezer 4 including a heat exchange coil 1 can be sterilized.