To prevent a large amount of air from flowing through a cabin at low cost even when an existing line train prasses through a tunnel, and relieve a phenomenon that an air pressure change outside the cabin transmits to the inside of the cabin.

A feeding device 4, an exhaust device 2, and an air conditioner 1 are formed integrally. Shutters 5 fitted on the feeding device 4 and the exhaust device 2 are opened and closed at a high speed according to a pressure change outside a cabin, and a door 10 is installed at the end structural part of a vehicle body. Since air flow in the cabin can be prevented even while a train is passing through a tunnel, it is possible to eliminate unpleasant feeling due to air flow itself and due to disturbance of cabin temperature balancing for relief of a cabin pressure change, thus relieving an ear-block feeling.