To provide a fluid-sealed vibration isolator of a novel structure which can effectively exhibit a target vibration isolation effect by sufficiently securing a pressure variation in positive pressure exerted to a pressure-receiving chamber, can prevent the abrupt change of pressure when a large pressure variation in negative voltage is generated in the pressure receiving chamber, and can reduce or avoid the generation of noise and vibration caused by the separation and the fadeaway of a vapor phase.

A gas holing member 72 which is harder than a main-body elastomer 16, and has specific gravity smaller than that of a non-compressive fluid sealed into the pressure receiving chamber 62 is accommodated and arranged in the pressure-receiving chamber 62, a gas retaining recess 76 is formed at least at one of the upper end face of the gas holding member 72 and the upper side wall face of the pressure receiving chamber 62, and the upper end face of the gas holding member 72 and the upper side wall face of the pressure receiving chamber 62 are tightly bonded to each other over the whole periphery which surrounds the circumference of the gas retaining recess 76.