An exhaust flow control valve includes: a valve plate hinged to a downstream exhaust pipe to be pivotable, inside the pipe, between a fully closed position where a short-cut hole is closed and a fully open position where the short-cut hole is opened, the valve plate having a tip end directed toward a downstream side of the downstream exhaust pipe when at the fully open position; a spring receiving member provided to the downstream exhaust pipe to traverse the short-cut hole; and a valve spring having one end portion fastened to a tip end portion, which is located on the downstream side of the downstream exhaust pipe with respect to the spring receiving member, of the valve plate, and having an opposite end side being slidably in pressure contact with the spring receiving member, thereby generating a repulsive force to bias the valve plate toward the fully closed position.