The present invention discloses a refrigerator with a water tank for supplying water to an ice tray by closing of a door. A refrigerator includes a cooling chamber for storing an article at a low temperature, an ice tray positioned in the cooling chamber and filled with water, for making ice, a water tank with a water supply hole for storing water and supplying water to the ice tray, and a valve for selectively opening and closing the water supply hole. In addition, a refrigerator includes a cooling chamber for storing an article at a low temperature, a main body for defining the cooling chamber, a door for opening and closing the cooling chamber, an ice tray positioned inside the door and filled with water, for making ice, a water tank with a water supply hole for storing water and supplying water to the ice tray, and a valve for selectively opening and closing the water supply hole.