PURPOSE: To prevent the generation of shock vibration and elongate the life of the title heat pipe by removing all obstacles regulating the circulating direction of operating liquid from the operating liquid circulating flow passage of a loop type fine tube container.

CONSTITUTION: A predetermined part of at least one place of a loop type fine tube container 1, formed by connecting both terminals of fine tubes so that fluid can be conducted in the tubes in the shape of a loop, is constituted so as to be a heat receiving section 1-H while a predetermined part of at least one place of the remaining section is constituted so as to be a heat dissipating section 1-C and the heat receiving sections and the heat dissipatingsections are arranged alternately in the most part of the container. Two-phase condensable operating fluid 4 of a predetermined amount, smaller than the total volume of the container, is sealed in the loop type fine tube container 1 while the diameter of the inner wall of the fine tube is designed so as to be smaller than the maximum diameter capable of circulating or moving the operating fluid in a condition of blockading the tube at all times. This means that a gas phase volumetric section, necessary for generating nuclear boiling in the heat receiving section, is necessitated so that the operating liquid can be moved while reacting against the vapor pressure of the nuclear boiling in the heat receiving section sensibly.