A loop heat pipe includes an evaporator to cause a liquid-phase working fluid to be vaporized by heat from a heat source; a condenser to condense the vaporized working fluid; a circulation path including a liquid line and a vapor line to connect the condenser and the evaporator in a loop; a tank provided on the liquid line and configured to accommodate the liquid-phase working fluid; a connecting line to connect the tank and the evaporator to supply the liquid-phase working fluid to the evaporator; and a bypass line positioned over the connecting line in a direction of gravity and connecting the evaporator and the tank, the bypass line being configured to discharge a vapor bubble produced in the evaporator during operation of the loop heat pipe to the tank.