PURPOSE:To effectively attenuate the vibration generated by a machine tool by installing a damper block into the lower part of an adjusting bolt and supporting said damper block onto a fitting recessed part installed on a supporting board by forming a minute gap and pouring liquid into the minute gap. CONSTITUTION:When vibration is applied onto a machine tool, a relative shift is generated between a supporting board 22 and a damper block 27 installed in the lower part of an adjusting bolt 20 which is screwingly fixed onto a bed 21. At this time, variation is generated in the minute gap 33 between the damper block 27 and the side surfaces 28 and 30 of a fitting recessed part 32 and the bottom surfaces 29 and 31. The viscous resistance of the viscous liquid 34 which is generated by the vibration of the minute gap 33 forms a damping force, and vibration is attenuated, and the relative shift is reduced.