PURPOSE: To improve the drive feeling in the vertical direction in the traveling at a slope change point by obtaining the inertial force in the vertical direction which is applied to a car body which is calculated from the traveling distance, slope point data of a rail, and the traveling speed and controlling the air feed and exhaust of a pneumatic spring.

CONSTITUTION: As for a railroad rolling stock equipped with e pneumatic spring, a height detector 7 for detecting the height of the pneumatic spring is installed between a truck 1 and a car body 2, and the detection signal is inputted into a controller 9, together with the pulse signal 10 supplied from a speed type power generator installed on a wheel axis. The valve opening and closing of an air feed valve 5 and an exhaust valve 6 which are installed midway in an air pipe 8 is controlled. The slope change point data is stored previously in the controller 9, and when a vehicle travels at the slope change point having a projection, the average height variation value ha of the pneumatic spring is set to the value for generating the relation: ha<ho for the standard height ho. Accordingly, at the starting point A of the slope change, the height of the car body is set lower than the standard value, and the height of the car body is increased by the upward inertial force.