Abstract: A support device configured to support a battery pack including a first battery accommodating portion arranged in a first space between a pair of side rails constituting a ladder frame of a vehicle, a second battery accommodating portion arranged in a second space below the first space and continuous with the first battery accommodating portion, and batteries accommodated in the first and second battery accommodating portions. The support device includes a frame-side bracket having first brackets extending from each of the side rails outward in a vehicle width direction and downward and a second bracket connecting the first brackets to each other below the battery pack, a battery-side bracket projecting from an end surface on an outer side in the vehicle width direction of the second battery accommodating portion outward in the vehicle width direction, and an elastic coupling portion elastically connecting the frame-side bracket and the battery-side bracket.