PURPOSE: To effectively cool with less heat resistance and rapid thermal response by a method wherein a heat sink of a metallic block is disused, and the heat absorption part of a heat pipe is put in direct contact with a flat heat generator.

CONSTITUTION: The heat absorption part 4 of the heat pipe is made of a thin metallic flat plate, the outer surface is in pressure-contact with heat dissipating planes of the flat heat geneators 1 and 2 as a heat absorption plane, and the inner wall surface is incontact with heat pipe operating liquid and is supported by a pressure resistant supporter 6. The pressure resistant supporter 6 consists of hollow metallic tubes 6-1... and a hollow metallic outer tube 6-8 which ties them up in a bundle, and the outer tube 6-8 is provided with circulation holes 12-1,... in order to use the spout of the vapor of the operating liquid and to enlarge a heat absorption area and a heat dissipating area. The heat dissipating part 5 of the heat pipe has a heat dissipating fin 5-1, and wicks 7 and 8 are loaded to uniformly distribute the operating liquid over the entire body inside the pressure resistant supporter.