To provide a vibration isolation device, in which vibration of a mechanical mode frequency resulting from the internal structure of the vibration isolation device is reduced with a simple structure.

This vibration isolation device 10 comprises a lower plate 11, an upper plate 12 and a middle plate 13 horizontally disposed in parallel from each other; a first viscoelastic body 16 connecting the lower plate to the upper plate through a through-hole of the middle plate; and at least three first compression coil springs 14 and second compression coil springs 15 each disposed around the viscoelastic body so as to extend in the vertical direction between the lower plate and the middle plate and between the middle plate and the upper plate, respectively, in which the corresponding first and second compression coil springs are disposed around the center line of the first viscoelastic body to be point symmetric or at equal angular intervals. The device 10 further comprises a plurality of second viscoelastic bodies 17 extending in the vertical direction so as to connect the lower plate to the middle plate, the second viscoelastic bodies being disposed in positions never interfering with the first compression coil springs relative to the horizontal direction between the lower plate and the middle plate.