A suspension tower has: a top plate at which an upper end side of a front suspension is fixed at a fixing portion that is disposed apart from a stroke axis of the suspension; and a gradually changing rib that is provided upright from the top plate and extends from the stroke axis side toward an outer peripheral side at the top plate. The gradually changing rib has a constant level portion whose height from the fixing portion is constant, and a gradually changing portion whose height from the fixing portion is gradually decreased from the constant level portion toward the outer peripheral side. A boundary between the constant level portion and the gradually changing portion is disposed adjacent to the fixing portion.