A heat exchange flow path portion is formed by alternately winding two spirally-shaped first and second heat transfer walls, with a predetermined gap interposed therebetween in the radial direction of the flow path pipe, around the outer periphery of a cylindrical flow path pipe, in which a cooling heat source is disposed in a main heat transfer flow path inside thereof. An inlet flow path and an outlet flow path for introducing compressed air into the flow path pipe and discharging compressed air from the flow path pipe are alternately formed, in the radial direction, from the gap between the heat transfer walls. Heat exchange is performed between compressed air that flows in the flow path and compressed air that flows in the flow path.