A control signal filter 2 receives a sound source signal determined by a control frequency specified in conformity with the vibration/noise source that produces vibration/noise, and outputs a control signal. A filter coefficient update unit 4 updates coefficients of the control signal filter 2 in response to a sound source signal and an error signal. A signal-to-interference ratio measuring unit 5 outputs a signal-to-interference ratio determined from the vibration/noise and the interference contained in the error signal in response to the control frequency and error signal. An update controller 6 adjusts an update step of the filter coefficient update unit 4 in accordance with the signal-to-interference ratio.