To provide a vibration isolation apparatus capable of detecting occurrence of an earthquake without needing an earthquake detection sensor nor stopping acceleration feedback loop control.

This active vibration isolation apparatus includes: a vibration isolation stand for mounting an apparatus thereon; an air spring supporting the vibration isolation stand; an actuator device driving the air spring; a linear motor device for vibration isolation; a position measurement means measuring the position of the vibration isolation stand; a vibration measurement means measuring vibration of the vibration isolation stand; and a control device of the actuator device and the linear motor device for vibration isolation having a position feedback loop based on the output of the position measurement means and an acceleration feedback loop based on the output of the vibration measurement means; and is characterized by detecting the earthquake by a square integrated value of a control current of the acceleration feedback loop upon earthquake occurrence.