PURPOSE: To restrict the earthquake response of the vertical pump by providing the bottom of barrel casing with a board having cross-shaped section and arranging it in fluid.

CONSTITUTION: The board 9 having the shape of a cross is provided at the bottom of the vertical pump 3. A vessel 12, having a wall surface 11 opposing to the board 9 with a predetermined clearance 10, is provided at the bottom of a concrete pit 2 while the inside of the vessel 12 is filled with the fluid 13. A plastic member 14 is provided above the vessel 12 and is constituted so that it is contacted with the bottom of the vertical pump 3 closely to permit to prevent the leakage of the fluid 13. When the tip end of the vertical pump is vibrated, a flow is generated in the fluid 13 due to the relative displacement between the cross-shaped board 9 and the wall 11 of the vessel and thereby permitting to increase the attenuation of the vibration.