The invention offers an air spring for obtaining a vehicle that renders good comfortableness even at the time of the curved-track running. The air spring for a vehicle has an upper board, a lower board, a diaphragm, and a stopper rubber placed between the lower board and a lower plate. The air spring is provided with a mechanism for restraining the displacement of the stopper rubber, the mechanism having a first restraining member placed on either one of the lower plate and the lower board and a second restraining member placed on the other. The shape of restraining wall surfaces is formed such that in the relative positional relationship between the first and second restraining members, when the first or second restraining member displaces itself such that it delineates an arc by placing the center at the railway truck axis of the railway truck of a vehicle, the spacings between the first and second restraining members at the left side and right side are equal to each other or decrease as the amount of displacement along the arc increases.