To provide an earthquake-proof device for a table, which can stop the propagation of vibration from the floor to an OA(office automation) apparatus and which can maintain the horizontal posture of the OA apparatus without necessitating troublesome installing/removing work for fixation of the OA apparatus and without damaging the beautiful appearance of the OA apparatus.

A floor 5 on which an OA table 7 is mourned is prepared indendent of other floors 6. Shaft part 1a, 1b of the OA table 7 are fixed to the rear surface of the mounting surface, while an acceleration sensor part 2 is attached to the mounting surface of the OA table 7. The shaft parts 1a, 1b have magnetism, and their side and bottom surfaces are surrounded by shaft receiver controlling parts 4a-1, 4a-5, 4a-9, 4b-1, 4b-5, 4b-9. The acceleration sensor part 2 detects the vertical and horizontal acceleration of the floor 5, and CPUs 3a, 3b controls the shaft receiver controlling parts 4a-1, 4a-5, 4a-9, 4b-1, 4b-5, 4b-9 so that the acceleration becomes zero and moreover the floor 5 floats in the air.