To provide a new, convenient, and low-cost geothermal heat recovery utilization system excellent in the efficiency and rationality of utilizing heat by considerably mitigating burdens such as the cost of construction and equipment and an effort for the construction.

The geothermal heat recovery utilization system is characterized in that: an area to 6m of an underground depth is set to be an effective heat collecting area; and a heat collecting tube is buried in the ground by being inserted into a dug underground opening and by filling the opening with dug soil; a heat collecting tube unit is connected and buried in the ground in a U-shaped manner to arrange the heat collecting tube; a liquid medium circulates in the heat collecting tube; and the geothermal heat is recovered for utilizing the geothermal heat.