A suspension device according to one embodiment of the present disclosure which is equipped with an upper arm, a lower arm, and a leaf spring positioned so as to extend in the vehicle widthwise direction in a manner such that an end section thereof is provided in the lower arm, wherein: the lower arm has an opening which opens to the inside in the vehicle widthwise direction; the leaf spring extends into the lower arm through the opening; the end section of the leaf spring is supported by a support part of the lower arm; and a cover section of the lower arm covers the end section of the leaf spring at a distance therefrom, and has a prescribed reinforcing shape.