To provide a seismically isolated structure of floor-standing apparatus, wherein the structure can prevent the floor-standing apparatus from falling down even against a large shake of a floor.

A first base-isolation material 3 is interposed between at least at four corners on the reverse side of a base 2 on which floor-standing apparatus 1 is placed, and a floor surface 5. A second base-isolation material 4 is interposed between the surface of the base 2 and the floor-standing apparatus 1. The horizontal vibration propagation ratio of the second base-isolation material 4 is made different from that of the first base-isolation material 3.