To provide a method for performing heating and cooling at small heat gathering/heat radiating cost, by using a constant temperature area artificially prepared for an underground shallow part for heat accumulation during a season.

This constant temperature layer is prepared by preventing influence on the underground temperature by a change in the air temperature by the season and a change in the direct sunlight, by constructing a heat insulating layer by embedding a heat insulating sheet 2 prepared in advance in the underground shallow part or using any heat insulating material. A shallow test conical hole 4 is excavated for horizontally laying or vertically or obliquely laying a U tube 5 in this artificial constant temperature layer, and the U tube is inserted. When it is difficult for insertion since a wall collapses, help of a U tube inserting bar is borrowed, or a U tube pipe of inserting the U tube in advance into a pipe is also prepared, to surely insert the U tube into the test conical hole. A tank is embedded or prepared in the constant temperature area of the underground shallow part, and water is inputted as a heating medium, and the heating and cooling is performed by the heat accumulation during the season, to expand a width of a choice.