PURPOSE: To perform an effective and positive utilization of radiation heat got from a compressor, an efficient defrosting, enable heating of refrigerant returned back to the compressor to be easily carried out and then to provide a small-sized freezing cycle system having a simple structure without requiring any large-sized mounting space.

CONSTITUTION: A heat accumulating tank 11 having a heat absorption heat exchanging coil 10 is integrally arranged to cover a case of a compressor 1 and further arranged in such a manner that it can be heat exchanged with the compressor 1 and then the heat absorbing heat exchanging coil 10 is used for defrosting operation during a heating operation.