To provide an air conditioning system using underground heat, stably and permanently usable for twenty four hours by using a stable geothermy of 5-7 m in the underground having a temperature of approximately 16C throughout the year, eliminating maintenance work, having a small number of construction sections, reducing processes, improving construction accuracy, shortening a construction period, drastically reducing construction cost, preventing the generation of a carbon dioxide and saving energy.

The air conditioning system using underground heat includes an underground heat conduction material 1 embedded in the underground and performing the absorption and conduction of heat only by using metal; an on-ground heat conduction material 2 installed on the ground and performing the conduction and release of heat by using only metal; a connecting part heat conduction material 3 embedded in the underground upper section and performing the connection and conduction of the underground heat conduction material 1 and the on-ground heat conduction material 2 only by using metal; a heat release box 4 positioned on the ground and releasing heat from the on-ground heat conduction material 2; and ducts 5, 6 for circulating and sending the heat of the heat release box 4 to an indoor side.