To provide a fluid-sealed type vibration isolation device including a new structure that exhibits an effective vibration isolation effect for any of an axial vibration and an axially perpendicular vibration, and secures sufficient durability even when an axial static load acts, and to provide a method of manufacturing the vibration isolation device.

An intermediate sleeve 22 fixed on the outer peripheral surface of a main rubber elastic body 16 has a structure where a first ring part 24 and second ring part 26 that are separately arranged in the axial direction are interconnected through a plurality of connection bridges 28. Thin wall parts 40 are fixed on this first ring part 24, thick wall parts 42 thicker than the thin wall part 40 are fixed on the second ring part 26, and a part of a wall part of a pressure receiving chamber 80 is constituted by the thick wall parts 42. The connection bridge 28 includes a deformation region 110 where the first ring part 24 and second ring part 26 are closely deformed and circumferentially and plastically deformed. The thin wall part 40 includes a pre-deformation section 104 loosened by the forming of the deformation region 110.