A suspension device for suspension of an axle 2 by an intermediate portion of a single leaf spring 5 has first restriction means which restricts, upon breakage of the leaf spring 5 at a position behind the intermediate portion of the spring, the rear portion of the leaf spring 5 from tilting downwardly relative to a shackle 6, and a second restriction means (retainer pawl 13) for restriction of the shackle 6 from pivotally moving backward beyond a predetermined angle. The first restriction means is constituted by a stopper plate 12 (stopper) on the shackle 6 for support of the rear portion of the leaf spring 5 from below upon breakage.