To provide a heating device for a heat pipe capable of uniformly heating the outer peripheral part of the heat pipe using heat generated from an electric heater, to allow an operating fluid in the heat pipe to flow being heated with the stable heat transfer amount.

This heating device 10 for the heat pipe is a structure composed of a first divided cylindrical body 20 and a second divided cylindrical body 30. The first divided cylindrical body 20 comprises a heat conductor 21 wound around the heat pipe 11; a sheathed heater 23 serving as an electric heater 22 wound around the heat pipe 11 through the heat conductor 21; and a heat insulating structure 13 adjoining the outer periphery of the sheathed heater 23. The second divided cylindrical body 30 comprises a heat conductor 31 wound around the heat pipe 11; a sheathed heater 33 serving as an electric heater 32 wound around the heat pipe 11 through the heat conductor 31; and a heat insulating structure 34 adjoining the outer periphery of the sheathed heater 33. The heating device 10 is further provided with a clamp 16 used as a pressing means 15 for pressing the sheathed heaters 23, 33 to the heat pipe 11 side to compress the heat conductors 21, 31 after allowing the first divided cylindrical body 20 and the second divided cylindrical body 30 to coincide with each other.