To provide a base isolation device capable of absorbing vertical swinging and lateral swinging of a building, superior in the base isolation function, inexpensive with a simple structure, and suitable for a relatively small-scale building such as a wooden building and a low story concrete building.

A pan surface 9 forming a downward inclination toward a central part, is arranged on an upper surface of a base member 1 fixed on a foundation of the building. A vertically movable sleeve 3 and an elastic body 4 contractibly arranged between this sleeve 3 and an upper quake receiving member 2, are held by the upper quake receiving member 2 fixed to a sill. The sleeve 3 is arranged on a steel ball 5 rollably arranged on the pan surface 9 of the base member 1. The base member 1 and the upper quake receiving member 2 are joined by a plurality of latch mechanisms 6 vertically joined so as to be engageable and disengageable and a plurality of springs 7 for mutually drawing the base member 1 and the upper quake receiving member 2.