PURPOSE: To enhance the transporting performance of heat by increasing the moving speed of a fluid between a cooling portion and a heating portion by providing a screw pump device in the inside of the cylinder of the cooling portion at least in a heat pipe.

CONSTITUTION: When heating the heating portion B of a heat pipe 1 turning in the direction of arrow C, for example, a liquid fluid 5 in the heat pipe 1 is vaporized and the vapor 5a is directed through the central part of the cylinder 2 to a cooling portion A by the difference in the pressure in the cylinder 2. The fluid 5a in the state of steam in the cooling portion A is adhered to a propeller 3 and condensed while releasing its heat through the propeller 3 as a heat conductor. The fluid 5 so condensed is quickly returned to the heating portion B by means of the spiral propeller 3 in contact with the inner surface of the cylinder 2, again vaporized, and then directed to the cooling portion A. These processes are repeated. Since the movement of the fluid between the cooling portion A and the heating portion B is hastened, the heat transporting performance of the heat pipe can be greatly increased.