To provide a heat pipe that does not cause a decrease in condensation even if an uncondensed gas is mixed.

Two kinds of incompatible refrigerants 14 and 16 are accommodated in a container. The liquid density of the second refrigerant 16 is smaller than that of the first refrigerant, and its boiling point is higher than that of the first refrigerant. The first refrigerant 14 heated by a heating element 24 is boiled, and sent to the layer of the second refrigerant 16 in a liquid state as bubbles 14v. The bubbles 14v of the first refrigerant are cooled by the second refrigerant 16 and a radiator 26 in the second refrigerant 16, and the first refrigerant 14 is condensed, thus turned into droplets 14aq. The droplets 14aq are descend and returned to the layer 14L of the first refrigerant in a liquid state. Since the first refrigerant is condensed in the second refrigerant, the condensed droplets 14aq are not enclosed by a thick layer of an uncondensed gas, and there occurs no hindrance of the heat or substance movement by an uncondensed gas.