To provide a vibration isolator comprising an outer cylinder, an inner cylinder and a rubber elastic member connecting both the cylinders to each other, in which the deformation stroke of a stopper rubber is enlarged so that the dynamic spring constant is prevented from being raised as much as possible.

The vibration isolator is provided with the outer cylinder, the inner cylinder and the rubber elastic member between both the cylinders, connecting the cylinders to each other. Two clearances are defined between the outer cylinder and the inner cylinder by the rubber elastic member. The inner cylinder and the outer cylinder are attached to a vibration generating source and a skeleton. The vibration isolator has the stopper rubber extending from the outer cylinder toward the inner cylinder in at least one of the clearances, with a gap a interposed between the top end of the stopper rubber and the inner cylinder. The outer cylinder is provided with a recessed portion for a base portion of the stopper rubber, and the base portion is received in the recessed portion. The outer cylinder is denoted by 1; the recessed portion is denoted by 1a; the inner cylinder is denoted by 2; the rubber elastic member is denoted by 3; the stopper rubber is denoted by 4; the base portion of the stopper rubber is denoted by 4b; the gap between the top end of the stopper rubber and the inner cylinder is denoted by a; a height of the stopper rubber is denoted by b; and a distance between the outer cylinder and the inner cylinder is denoted by c.