The present disclosure provides a refrigerator operation control method capable of accurately recognizing whether an abnormal situation occurs as well as determining a defrosting time using an identified rotation speed of a blowing fan.

A container refrigeration apparatus includes a cooler including a compressor, a radiator, an expansion mechanism, and an evaporator and being configured to perform, by the evaporator, a cooling operation of cooling an inside of a container, a ventilator configured to supply outside air into the container, and a processor configured to control the cooler and the ventilator, wherein the processor is configured to adjust a cooling capability of the cooler, based on a ventilation cooling load that is a cooling load in accordance with a ventilating operation of the ventilator.