To achieve stable high speed operation by correcting a variation in attitude of a vehicle with good responsiveness in operation of a steering wheel or the like at a time of acceleration.

A vehicle height adjustment device, which changes vehicle height by vertical movement of a shaft member (21) activated by rotation of the shaft member or a receiving member (30), is intervened between a wheel (11) and a vehicle body (14), while the vehicle height adjustment device is driven based on the steering amount of the steering wheel, vehicle speed and vehicle acceleration, to secure the horizontal attitude of the vehicle during traveling. Quick adjustment of the vehicle height is also achieved by the adjustment with the rotation of the shaft member or the receiving member. The vehicle height adjustment device may be constituted in such a manner that a spiral groove is provided either to the shaft member or the receiving member, and that a sliding projection to be engaged with the spiral groove is provided either to the shaft member or the receiving member.