PURPOSE: To improve the fluid circulation by the heat exchanging device and contrive to increase the transferring heat quantity by shortening the length of pipe lines connecting between an evaporating pipe group and a condensing pipe group.

CONSTITUTION: A single pipe 9a is provided hanging down from an upper header 8 in a condensing pipe group, and a single pipe 5a for receiving of a water is installed in upright position on a lower header 4 in an evaporating pipe group. Thereby, a vapor nozzle 18 as a vapor receiving port and a fluid nozzle 19 as a water flowing out port can be installed closely, and located at a lower header 10 side opposing to the evaporating pipe side. On the other hand, a vapor nozzle 20 of an upper header 6 of the evaporating pipe group and a fluid nozzle 21 of the upper end part of the single pipe 5a can be installed closely and located at the upper header 6 side. Therefore, pipe lines 22, 23 connecting those nozzles can be arranged in close and parallel manner, formed in compact structure. By said structure, the length of the connecting pipe lines between the condensing pipe group and evaporating pipe group can be shortened, accordingly, the pressure drop is decreased, and the heat transferring effectiveness can be improved.