Abstract: A sphere is attached to a holding table receiving a load of an object. A friction contact surface taking the shape of an internal surface of a sphere which comes in contact with the sphere is formed on the holding table. The friction contact surface is formed between a circular small diameter edge and a circular large diameter edge, the circular small diameter edge having a certain radius from a vertical line passing through a center of the sphere, and the circular large diameter edge setting, as a maximum radius, a radius along a horizontal surface passing through a center of the sphere. With increasing an acceleration of the earthquake, a state in which the sphere is horizontally moved integrally with the holding table is changed into a state in which the sphere comes in sliding contact with the friction contact surface to spin in the holding table.