PURPOSE: To improve vibration-proof performance by choosing an electrode to which a voltage is applied based on detected signal, and changing the form of a liquid chamber and the form of an orifice, so as to control passing direction of electro-viscous fluid passing through the orifice.

CONSTITUTION: The vibration isolator in the title is composed so as to three dimensionally arrange many electrodes 9, 14-19 in a main chamber 12 in which liquid L is enclosed and a square hole 11a, to serectively apply voltages to said electrodes 9, 14-19 to generate a high viscous wall based on detected signal from an acceleration sensor 24, and to divide the main chamber 12 and the square hole 11a to plural number of liquid chambers and orifices for connecting neighboring liquid chambers to each other with this high viscous wall. Therefore, different from a traditional art in which the flow direction of magnetic liquid L passing through the orifice is only one it becomes possible to surely damp vibration in three axial directions, in X axial direction, Y axial direction, and Z axial direction so as to attempt improvement in vibration-proof performance.