To obtain the support structure of a recirculation pump capable of supporting while damping well vibration of the recirculation pump without using a receiving frame interfering with apparatuses of containment bottom.

A plurality of hanging hooks 7 are provided to a recirculation pump 4 placed on a circulation line L extending from a reactor pressure vessel 1, the recirculation pump 4 is hung with the hanging hooks 7 at a specified position and each hanging hook 7 is supported while damping with a plurality of vibration suppression connectors 14 extending from containment inner wall and beam 9 side. By this, the recirculation pump is supported and simultaneously damped well without using a receiving frame 10 interfering with components of containment 8 bottom.