To provide a vibration isolation device capable of preventing the sealing performance in liquid filling work from deteriorating and capable of simplifying maintenance of apparatuses in relation with the liquid filling work. A liquid chamber is filled with liquid from a through hole through a nozzle. A seal section is vulcanizingly formed in the periphery on one end side of the through hole. Because the seal section interferes with a nozzle and is elastically deformed, the sealing performance in pouring in the liquid can be secured. Also, because the seal section is arranged for every vibration isolation device, maintenance of a liquid filling device can be simplified compared with a case the seal section is arranged in the liquid filling device.