To provide an active engine mount device to execute constantly best vibration damping operation even when a secular change occurs to an engine mount and an engine foot and maintain a riding sensation in a best state.

Vibrations from an engine 7 and an engine mount 9 are synthesized and an error vibration transmitted to an engine foot 2 is detected as an error signal (e) by an error sensor 19. In a case where the error signal (e) exceeds a given value, devision that engine vibration is diverged is effected by an engine vibration divergence deciding part 51. An update indication signal is outputted to a fixed filter 27 from a transmission characteristic estimating value C* vibration indicating part 53 and updating is effected through movement through which the frequency of transmission characteristics stored at the fixed filter 27 is increased.