To provide an active vibration removing device having a control system by constituting pressure feedback or weighted feedback against active supporting legs in which a pair of air spring actuators are opposed to each other.

Output of differential manometers 31D of active supporting legs 2a-2c are negatively fed back on the input side of PI compensators 27a-27c provided on the preceding stage of voltage/current converters 12a-12c carrying current to four-way valve type servo valves 30a-30c through gain compensators 32a-32c and related to pressure. On the part positions differential pressure input terminals 33a-33c designating differential pressure of a pair of air springs in the active supporting legs 2a-2c are provided, and the initial posture of a vibration removing base 1 is decided by their designations. Such pressure feedback is provided independent of the respective active supporting legs 2a-2c. In addition to this, acceleration feedback and positional feedback are constituted, and together with them non-interacting control based on a motion mode is constituted.