To suppress a decrease in durability due to abrasion or breakage caused by a reduction of a supporting area of a stopper at the time a wrench is inputted. An inner cylinder and an outer cylinder are connected by an insulator. An inner cylinder side stopper of concave curve surface is formed on an outer circumference of an intermediate part in the longitudinal direction of the inner cylinder. On the other hand, an outer cylinder side stopper that projects toward the inner cylinder side stopper is provided on an outside of the inner cylinder side stopper. The outer cylinder side stopper is relatively moved in a recessed space of the inner cylinder side stopper so as to regulate the reduction of the supporting area.