A method of controlling a refrigerator is disclosed. The method includes: operating a cool air supply means with a predetermined output; a controller determining the output of the cool air supply means based on a current temperature of a storage compartment sensed by a temperature sensor while the cool air supply means operates with the predetermined output; and the controller operating the cool air supply means with the determined output. The controller determines that the output of the cool air supply means is decreased or increased when an absolute value of a difference between a previous temperature and a current temperature of the storage compartment is equal to or greater than a first reference value, and wherein the output of the cool air supply means is decreased or increased again when the absolute value of the difference between a current temperature of the storage compartment sensed again after a predetermined time has elapses and the previous temperature of the storage compartment is equal to or greater than the first reference value.