In a vibration isolator, stable liquid filling and assembling is obtained by reducing the effect of press-fitting a switching admission pipe. The vibration isolator including a partition having a partition main member and a partition plate member, a main liquid chamber, a first sub liquid chamber, a second sub liquid chamber and a switch chamber, orifices, and a switching admission pipe press-fit in a passage provided in the partition main member. A seal surface in contact with a seal rubber layer on an inner periphery of a cylindrical barrel is formed at around an opening end of a passage in an outer peripheral surface of the partition main member and a pressure-receiving surface broader than the other portion in the outer peripheral surface is provided on a side opposite to the seal surface sandwiching a device axis thereby effecting dispersal of external force during the press-fitting.