A vehicle substructure includes a panel in which an accommodating recessed portion is disposed, a battery holder attached to a bottom surface of the accommodating recessed portion, and a battery attached to the battery holder. The battery includes a first flange portion and a second flange portion. The battery holder includes a carrier on which the battery is mounted, a first clamp portion having the first flange portion interposed between the carrier and the first clamp portion, and a second clamp portion having the second flange portion interposed between the carrier and the second clamp portion. A spacer filled in a space between the first side surface and an inner wall surface of the accommodating recessed portion is disposed between the first side surface and the inner wall surface of the accommodating recessed portion and above the first clamp portion.