To provide a house using geothermal heat capable of achieving cooling and heating performance while reducing an air conditioning load of heating or cooling by taking the cooled air or warmed air of which heat is exchanged by geothermal heat in a moderate air amount into indoor areas while utilizing a 24-hour ventilation system.

A first floor under-floor part surrounded by a heat insulated foundation 12 is a heat storage space 13, an end 11a of a heat exchange pipe 11 buried in the ground is opened to the heat storage space 13, the other end 11b of the heat exchange pipe 11 is opened to the outside of the heat isolation foundation 12, a communication port 17 for communicating the heat storage space 12 with a first floor above-floor part 16 is provided, the warmed air or the cooled air is taken into the first floor above-floor part 16 from the heat storage space 13 by a 24-hour ventilation type ventilating device, and the outside air is taken-in from the other end 11b of the heat exchange pipe 11, and the warmed air or the cooled air of which heat is exchanged by the geothermal heat is supplied to the heat storage space 13.