Data including a power consumption amount and an ambient temperature of a heat exchanger that discharges heat to an outside of a cooling facility in an operation mode in which the facility is operated in an operation state that requires less power consumption than usual is extracted as degradation determination reference data before degradation determination, and data including the power consumption amount and the ambient temperature in the operation mode in which the cooling facility is operated in the operation state that requires less power consumption than usual is extracted as determination data, whereby the increase in the power consumption amount due to the influence of the disturbance that changes a temperature of an inside of a box-shaped housing can be excluded, and the degradation of the cooling facility can be correctly determined by grasping the increase in the power consumption amount due to aging degradation.