To provide a refrigerator comprising an automatic ice making machine having a water supply tank of high convenience in loading and using states. In this refrigerator, the water supply tank is composedof a container opened at its upper face, and a lid body for covering an upper face of the container, the water in the water supply tank is supplied to an ice tray by using a water supply pump, a bag-shaped portion projecting forward, is formed on a front face of the container excluding a wall for leading out a discharge portion of a water guide pipe, and the approximately L-shaped water guide pipe is led to the outside of the container from the wall for lead-out.