To enhance productivity by further enhancing the ease of assembly in a main assembly line in a suspension installation structure for a vehicle. Cantilever frames (that is, first inclined frames and lower main frames) that protrude toward the front of a vehicle (or toward the rear of the vehicle) are provided to a body frame. Brackets (that is, an upper bracket, a lower front bracket and a lower rear bracket) are fastened to the cantilever frames by bolts as a fastener.