To provide an inexpensive tire air pressure regulation air valve with a simple valve drive mechanism, less number of parts, and less failure.

The tire air pressure regulation valve is the one mounted to a rim 3 of a wheel 2 and regulating the air pressure in the tire 4, and has a valve stem 11 of a hollow shape communicated with the inside of the tire 4. A pressure-reduction means 19 for reducing the tire air pressure is provided in the valve stem 11, and is provided with a valve element 15 for opening/closing a leak hole 14a formed on the valve stem 11; an electro-magnet 52 for forcedly attracting the valve element 15 to release it; and a valve control part 56 for driving/controlling the electro-magnet 52.