A refrigerator, comprising: a cabinet in which a storage compartment is provided; a first door connected to the cabinet to open or close the storage compartment and having an opening; a housing provided in the first door and accessible through the opening therein; an ice making room provided in the housing; a second door connected to the first door; a dispenser disposed on a front surface of the second door and having a water faucet disposed on a top surface thereof; and a discharge duct provided in the second door, a main water supply tube extending along an inside of the top surface of the cabinet and exposed to an outside of the cabinet by passing through the top surface of the cabinet; a water tank mounted on the lower end of the first door and connected to a water source that is provided outside the refrigerator by a water supply hose; a switching valve mounted to an outlet of the water tank; and a dispenser water supply tube led into the second door through a lower hinge shaft, wherein the dispenser water supply tube extends along a space between the front surface of the second door and the front surface of the discharge duct, wherein the water faucet is disposed on a lower end of a funnel, or wherein the dispenser water supply tube extends along a space between a rear casing of the dispenser and a dispenser liner, and an end of the dispenser water supply tube is connected to the water faucet to dispense drinking water through the water faucet, or wherein the dispenser water supply tube is led into the second door and extends upward along the edge of the side surface of the second door to extend up to the water faucet, wherein the main water supply tube is led into the first door through an upper hinge shaft to be connected to an inlet of the water tank, and wherein the dispenser water supply tube is branched from the switching valve and passes through the front surface of a lower end of the first door to be exposed to the outside. a cabinet in which a storage compartment is provided; a first door connected to the cabinet to open or close the storage compartment and having an opening; a housing provided in the first door and accessible through the opening therein; an ice making room provided in the housing; a second door connected to the first door; a dispenser disposed on a front surface of the second door and having a water faucet disposed on a top surface thereof; and a discharge duct provided in the second door, a main water supply tube extending along an inside of the top surface of the cabinet and exposed to an outside of the cabinet by passing through the top surface of the cabinet; a water tank mounted on the lower end of the first door and connected to a water source that is provided outside the refrigerator by a water supply hose; a switching valve mounted to an outlet of the water tank; and a dispenser water supply tube led into the second door through a lower hinge shaft, wherein the dispenser water supply tube extends along a space between the front surface of the second door and the front surface of the discharge duct, wherein the water faucet is disposed on a lower end of a funnel, or wherein the dispenser water supply tube extends along a space between a rear casing of the dispenser and a dispenser liner, and an end of the dispenser water supply tube is connected to the water faucet to dispense drinking water through the water faucet, or wherein the dispenser water supply tube is led into the second door and extends upward along the edge of the side surface of the second door to extend up to the water faucet, wherein the main water supply tube is led into the first door through an upper hinge shaft to be connected to an inlet of the water tank, and wherein the dispenser water supply tube is branched from the switching valve and passes through the front surface of a lower end of the first door to be exposed to the outside.