To reduce cost by reducing the whole size and weight, while enlarging a spring ratio of a spring in the lateral direction to a spring in the vertical direction, in an exhaust system supporting rubber mount.

An upper boss part 3 forming an upper installation hole 2 is arranged in an upper part of an exhaust pipe supporting rubber mount 1 forming a substantially semicircular shape, and a cutout part 10 corresponding to a shape of cutting out the upper half part side of the upper boss part 3 is arranged in both end parts in its lateral direction. A lower half part of both end parts in the lateral direction of the upper boss part 3 corresponding to a part remaining after being cut out, forms a shoulder part 11 extending outward from the cutout part 10, and an upward opened semicircular extension groove 17 is arranged there. The spring in the vertical direction is made small by the cutout part 10, and since the spring in the lateral direction becomes large by compression in the shoulder part 11, the spring ratio of the spring in the lateral direction to the spring in the vertical direction is enlarged, and the whole is downsized by just that much.