A vibration isolation device comprising: a first attachment member formed in a tubular shape and coupled to a vibration generating unit or to a vibration receiving unit; a second attachment member coupled to the other of the vibration generating unit or the vibration receiving unit and disposed at the inner peripheral side of the first attachment member; a resilient body disposed between the first attachment member and the second attachment member and coupled to the first attachment member and the second attachment member; a partitioning member configuring a first main liquid chamber between the partitioning member and the resilient body in a main vibration input direction first end side of the second attachment member, the first main liquid chamber filled with a liquid from and the internal volume of the first main liquid chamber changing along with resilient deformation of the resilient body; a diaphragm member configuring an auxiliary liquid chamber between the diaphragm member and the partitioning member, the auxiliary liquid chamber filled with liquid and the internal volume of the auxiliary liquid chamber changing according to liquid pressure fluctuations; a first restricting through path enabling liquid to move between the first main liquid chamber and the auxiliary liquid chamber; a recess portion provided to the resilient body and configuring a liquid chamber between the recess portion and the first attachment member; a separating wall sectioning the liquid chamber into a plurality of second main liquid chambers (40A, 40B) in a row along a direction orthogonal to the axial direction of the first attachment member; a second restricting through path enabling liquid to move in-between the plurality of second main liquid chambers (40A, 40B) and/or between each of the second main liquid chambers (40A, 40B) and the auxiliary liquid chamber; and pressure difference reduction means (42U, 54) that reduces the pressure difference between the first main liquid chamber and the second main liquid chambers (40A, 40B); wherein the pressure difference reduction means (42U, 54) is provided to the separating wall; CHARACTERISED IN THAT: the pressure difference reduction means (42U, 54) is configured in the separation wall by thin walled portions on both sides of a thinned portion formed by thinning from a thickness direction central portion of the separating wall out towards the first main liquid chamber. a first attachment member formed in a tubular shape and coupled to a vibration generating unit or to a vibration receiving unit; a second attachment member coupled to the other of the vibration generating unit or the vibration receiving unit and disposed at the inner peripheral side of the first attachment member; a resilient body disposed between the first attachment member and the second attachment member and coupled to the first attachment member and the second attachment member; a partitioning member configuring a first main liquid chamber between the partitioning member and the resilient body in a main vibration input direction first end side of the second attachment member, the first main liquid chamber filled with a liquid from and the internal volume of the first main liquid chamber changing along with resilient deformation of the resilient body; a diaphragm member configuring an auxiliary liquid chamber between the diaphragm member and the partitioning member, the auxiliary liquid chamber filled with liquid and the internal volume of the auxiliary liquid chamber changing according to liquid pressure fluctuations; a first restricting through path enabling liquid to move between the first main liquid chamber and the auxiliary liquid chamber; a recess portion provided to the resilient body and configuring a liquid chamber between the recess portion and the first attachment member; a separating wall sectioning the liquid chamber into a plurality of second main liquid chambers (40A, 40B) in a row along a direction orthogonal to the axial direction of the first attachment member; a second restricting through path enabling liquid to move in-between the plurality of second main liquid chambers (40A, 40B) and/or between each of the second main liquid chambers (40A, 40B) and the auxiliary liquid chamber; and pressure difference reduction means (42U, 54) that reduces the pressure difference between the first main liquid chamber and the second main liquid chambers (40A, 40B); wherein the pressure difference reduction means (42U, 54) is provided to the separating wall;