To provide a mechanism without hindering restoration by frictional force, by using mechanical sliding frictional force as damping force, in a base isolation device using a ball and a bowl-shaped curved surface.

The bowl-shaped curved surface is formed on a surface respectively opposed to a foundation side pedestal 1 and na object side pedestal 5, and the ball is rollingly supported between its surfaces. A plate 8 pressed by a spring is arranged between an integrally connected plate 5 and a plate 11 for directly receiving an object. The bowl-shaped curved surface is also arranged by 3 to 4 sets on the opposed surfaces between 5 and 8. The ball is put in and supported between its curved surfaces. When the integrated 5 and 11 horizontally move, when the 8 vertically moves while receiving force in the horizontal direction, a sliding friction loss is caused between the 8 and a bar 12. Since driving force of this frictional force is transmitted by sliding contact, restoring force is not hindered.