Abstract: A system for drawing the open air indoors comprises an an open-air flow pipe and an open-air distribution pipe of which the respective one ends are made to communicate with each other. The open-air flow pipe is laid underground while its other end is made to communicate with an intake port provided above the ground. The other end of the open-air distribution pipe is made to communicate with the room of a building. The open air with which heat is exchanged under the ground during passing the open-air flow pipe and the open-air distribution pipe is drawn indoors, thereby allowing the room to be air-conditioned.