To provide a fluid holding device (a static pressure bearing and a static pressure guide) capable of restraining accuracy reduction in a moving body by a disturbance load of varying at a high speed.

This fluid holding device includes displacement sensors 9 and 10 for measuring relative displacement by disturbance force of a main spindle 3 and the static pressure bearings 4 and 5, and volume increasing-decreasing means 7 and 8 for increasing-decreasing the recess volume of a static pressure pocket, and restrains accuracy reduction in the fluid holding device by the disturbance force by increasing-decreasing the recess volume by the volume increasing-decreasing means 7 and 8 so as to restrain displacement detected by the displacement sensors 9 and 10.