To easily fill up a tire with high pressure air at low air pressure and improve running safety of a vehicle by forming the center part of a wheel into a double layer, providing a place receiving high pressure air (high pressure air chamber) therein, and providing an air injection valve so as to face to the high pressure air chamber.

A high pressure air chamber 3 capable of being filled up with high pressure air is formed on the center part of the outer circumferential part of a wheel on which an automobile tire is mounted, and an air injection valve 2 is provided so as to face to the high pressure air chamber 3. In case of low air pressure of the tire, for example, flat tire or slow flat tire, high pressure air in the high pressure air chamber is filled into the tire, to make a runnable condition. Namely the high pressure air chamber 3 and the air chamber of the tire are partitioned by a thin rubber film, and in case of flat tire by opening the thin rubber film by using an attached tool, high pressure air in the high pressure air chamber can be fed into the tire.