A refrigerator comprising: a cabinet configured to define an exterior boundary of the refrigerator with at least one opening therein; a first storage chamber defined by interior walls of the cabinet and configured to store food stuffs; a first door configured to open and close an access point to the first storage chamber by rotating about a vertical rotational axis; a second storage chamber provided in the first door, said second storage chamber being accessible from an outside of the first door; and a second door configured to open and close the second storage chamber by rotating about the vertical axis; characterised by: a supporting member provided between the second storage chamber and the second door and rotatably connected to the second storage chamber and configured to be moved in connection with opening and closing of the second door; and a motion conversion unit configured to convert rotation of the second door around the vertical axis into rotation of the supporting member with respect to a horizontal axis; wherein the motion conversion unit comprises a link member having a door connection part connected to the second door and a support connection part connected to the supporting member; and wherein the supporting member is configured to rotate around a support rotary shaft, when the second door is opened and closed. a cabinet configured to define an exterior boundary of the refrigerator with at least one opening therein; a first storage chamber defined by interior walls of the cabinet and configured to store food stuffs; a first door configured to open and close an access point to the first storage chamber by rotating about a vertical rotational axis; a second storage chamber provided in the first door, said second storage chamber being accessible from an outside of the first door; and a second door configured to open and close the second storage chamber by rotating about the vertical axis; characterised by: a supporting member provided between the second storage chamber and the second door and rotatably connected to the second storage chamber and configured to be moved in connection with opening and closing of the second door; and a motion conversion unit configured to convert rotation of the second door around the vertical axis into rotation of the supporting member with respect to a horizontal axis; wherein the motion conversion unit comprises a link member having a door connection part connected to the second door and a support connection part connected to the supporting member; and wherein the supporting member is configured to rotate around a support rotary shaft, when the second door is opened and closed. a supporting member provided between the second storage chamber and the second door and rotatably connected to the second storage chamber and configured to be moved in connection with opening and closing of the second door; and a motion conversion unit configured to convert rotation of the second door around the vertical axis into rotation of the supporting member with respect to a horizontal axis; wherein the motion conversion unit comprises a link member having a door connection part connected to the second door and a support connection part connected to the supporting member; and wherein the supporting member is configured to rotate around a support rotary shaft, when the second door is opened and closed.