PURPOSE: To prevent the trouble of whole of a cooling device by a method wherein a motor for ventilating a condenser is operated at the time of overload, an alarming device is operated upon the clogging of a condenser filter and the operation of a compressor is stopped at the time of uncommonness.

CONSTITUTION: A compressor temperature detecting means 9 detects the temperature of a compressor 7 and only when the temperature has become higher than a temperature A, set arbitrarily by a temperature setting means 12, upon overload, a motor 6 for ventilating a condenser is operated to increase the cooling effect of the compressor 7 whereby the temperature rise of the compressor 7 can be prevented. On the other hand, when a condenser filter 10 is clogged, an alarming device 11 is operated only when the temperature has become higher than a temperature B, set arbitrarily by the temperature setting means 12, whereby the sweeping of clogging of the condenser filter 10 is promoted. Further, upon abnormality, such as the trouble of the motor 6 for ventilating the condenser or the like, the operation of the compressor 7 is stopped forcibly only when the temperature has become higher than a temperature C, set arbitrarily by the temperature setting means 12, whereby the trouble of not only the compressor 7 but also the whole of a cooling device can be prevented.