To provide a building with a standing room for rehabilitation which is provided with atmosphere of one atmosphere and high oxygen concn. and makes it possible to do exercise under the atmosphere.

This building 100 is provided with an air supplying facility supplying air of average pressure and high oxygen density and at least one room 4 (excepting for a tent, etc., for temporary use) supplied with air of average pressure and high oxygen concn. The air of high oxygen concn. is transferred by pressure to the room 4 through a main pipe 3 connected to a high concn. oxygen generator 1. Then, a blow-out device of air transferred by pressure is installed to the ceiling of a room 4, e.g. in spite of not limiting an installing place in particular. If the building 100 is a medical facility such as a hospital, or the like, the room 4 supplied with air of high oxygen concn. can be used for rehabilitation or for preventing dementia, etc.