To shift the position of a spare tire carrier to a place separate from the side surface of a side rail while holding down the manufacturing cost.

A spare tire bracket 5B is fixed to the outside surface of a side rail and fitted with a spare tire carrier. The spare tire bracket includes: a pair of bracket main parts 51 having a projecting plate part 53 vertically projected from the outside surface and a flange part 54 bent at the base end of the projecting plate part 53 and joined to the outside surface; and tip connecting part 52 for connecting the respective tips of the pair of bracket main parts 51 to each other. Each projecting plate part 53 includes: a base end side part 53A formed substantially in a right triangular shape; and a tip side part 53B extended like a belt. A lower side part 53b of the base end side part 53A and the tip side part 53B are provided with spare tire carrier fitting parts 55, and a plate-like stiffener 60 of the substantially same shape as that of the part 53A and the part 54 is joined to the base end side part 53A and the flange part 54.