To provide a superior geothermal heat exchanger structure more efficiently transferring geothermal heat to a heat exchanger, and collecting the geothermal heat from a wide region by a long spiral pipe in comparison with a shallow construction depth.

In the geothermal heat utilization heat exchanger soil column having a multilayered concentric spiral pipe arrangement, the plurality of soil columns improved in heat conductivity by mixing metallic fiber f and metallic powder, are continuously formed on the ground, and joined to the geothermal heat exchanger in the soil column to increase a contact area with the ground and to increase a volume of a geothermal heat conduction passage, thus heat collecting effect is improved.