A centralized-monitoring apparatus, which centralized monitors a device including a storage, a temperature sensor to detect a temperature therein, and a temperature-variable device to cool or heat inside the storage such that the temperature reaches a set object-preservation temperature, comprises: an input device to be input with first information indicative of a time zone in which the temperature-variable device performing power-saving operation and second information indicative of a set temperature of the time zone; a storage device to store the first-and-second information from the input device; a timing device to measure a current time; and a control device to control the temperature-variable device, based on the first-and-second information and current time, so as to start operation of turning the temperature to the set temperature when the current time reaches a starting time of the time zone, and terminate the operation when the current time reaches an ending time thereof.