To make it economical by using a blower combinedly used for a wind tunnel device and a building exhauster by providing a vertical wind tunnel for free-falling simulation, which discharges air outside, a building exhaust duct connected to a blower inlet, an outlet exhaust passage connected to the outlet, and damper, which opens and closes an air inlet.

In the case of exhausting only from building, a damper 22 of an air inlet 21, and an outside air damper 25 is closed, an axial blower 11 discharges exhaust from the building from an exhaust vent 27. When floating is carried out in a floating chamber 7, the damper 22 and the outside air damper 25 are opened, and output of the axial blower 11 is increased. At this time, flow velocity of the blower 11 should be sufficient to float a person to be floated in the floating chamber 7. The opening of the damper 22 at full-opening is set so that the flow rate of an exhaust passage 26 is equal to independent discharging for reducing influence by opening the damper 22 on the building exhaust system. When suspension is carried out, the actual falling state is simulated by fluctuating diagonal wind and flow velocity by operating a mixed flow/fluctuated wind generating airfoil 13.