A refrigerator includes a carbonated water tank in which carbonated water is stored; a water level sensor sensing a water level of carbonated water stored in the carbonated water tank; a water tank supplying filtered water to the carbonated water tank; a carbon dioxide cylinder supplying carbon dioxide to the carbonated water tank; and a controller, if the water level of carbonated water sensed by the water level sensor is less than or equal to a predetermined minimum water level, supplying the filtered water to the carbonated water tank, and if supply of the filtered water is completed, supplying the carbon dioxide to the carbonated water tank so as to produce the carbonated water. If the carbonated water is discharged, the controller controls the water level sensor to sense the water lever of the carbonated water stored in the carbonated water tank.