Vibration isolation device

A vibration isolation device comprising:

• a lower plate fixedly arranged horizontally;
• an upper plate arranged horizontally above this lower plate with a predetermined interval and supporting a supported object;
• a viscoelastic body connecting the lower plate and upper plate to each other;
• and
• compression coil springs arranged between the lower plate and upper plate in the vertical direction, wherein the coil springs are arranged at positions of a plurality of pairs with an equiangular interval in point symmetry around a center line, extending vertically from the lower plate toward the upper plate, and each comprised by a coil spring with a free length longer than an outer diameter, and the viscoelastic body is arranged axisymmetrically with respect to the center line of the upper plate and lower plate and inclined with respect to this center line, and wherein the viscoelastic body is arranged in a hollow cylinder portion extending in a longitudinal direction and having an upper end fixed to one of the lower plate and the upper plate, with the lower end arranged opposite to an inclined face of a receiving mount on the upper plate or the lower plate side and compressed/adjusted in the longitudinal axis direction by an adjusting screw capable of insertion to/removal from the hollow cylinder portion, and a receiving plate mounted to an end face of the lower end is pulled by a tension spring and housed into the hollow cylinder portion.