An oscillator circuit comprising: an oscillator operable to perform a vibration while being driven by a driving signal, and outputs a monitoring signal according to the vibration; a filter operable to filter the monitoring signal and to output the filtered monitoring signal; a driver operable to amplify the filtered monitoring signal to generate the driving signal; and a controller operable to control a passing frequency band of the filter based on the monitoring signal, wherein the oscillator is operable to perform a sensing vibration according to an amount of inertia applied from outside of the oscillator, characterized in that: the controller includes a frequency measuring section including a reference oscillator for generating a reference signal, the frequency measuring section operable to measure a frequency of the monitoring signal based on the reference signal, and the controller is operable to: adjust a center frequency of the passing frequency band of the filter based on the frequency of the monitoring signal so as to cause the center frequency to become lower than the frequency of the monitoring signal in a case that a frequency of the sensing vibration is higher than the frequency of the monitoring signal, and adjust the center frequency of the passing frequency band of the filter so as to cause the center frequency to become higher than the frequency of the monitoring signal in a case that the frequency of the sensing vibration is lower than the frequency of the monitoring signal. an oscillator operable to perform a vibration while being driven by a driving signal, and outputs a monitoring signal according to the vibration; a filter operable to filter the monitoring signal and to output the filtered monitoring signal; a driver operable to amplify the filtered monitoring signal to generate the driving signal; and a controller operable to control a passing frequency band of the filter based on the monitoring signal, wherein the oscillator is operable to perform a sensing vibration according to an amount of inertia applied from outside of the oscillator, characterized in that: the controller includes a frequency measuring section including a reference oscillator for generating a reference signal, the frequency measuring section operable to measure a frequency of the monitoring signal based on the reference signal, and the controller is operable to: adjust a center frequency of the passing frequency band of the filter based on the frequency of the monitoring signal so as to cause the center frequency to become lower than the frequency of the monitoring signal in a case that a frequency of the sensing vibration is higher than the frequency of the monitoring signal, and adjust the center frequency of the passing frequency band of the filter so as to cause the center frequency to become higher than the frequency of the monitoring signal in a case that the frequency of the sensing vibration is lower than the frequency of the monitoring signal. the controller includes a frequency measuring section including a reference oscillator for generating a reference signal, the frequency measuring section operable to measure a frequency of the monitoring signal based on the reference signal, and the controller is operable to: adjust a center frequency of the passing frequency band of the filter based on the frequency of the monitoring signal so as to cause the center frequency to become lower than the frequency of the monitoring signal in a case that a frequency of the sensing vibration is higher than the frequency of the monitoring signal, and adjust the center frequency of the passing frequency band of the filter so as to cause the center frequency to become higher than the frequency of the monitoring signal in a case that the frequency of the sensing vibration is lower than the frequency of the monitoring signal. adjust a center frequency of the passing frequency band of the filter based on the frequency of the monitoring signal so as to cause the center frequency to become lower than the frequency of the monitoring signal in a case that a frequency of the sensing vibration is higher than the frequency of the monitoring signal, and adjust the center frequency of the passing frequency band of the filter so as to cause the center frequency to become higher than the frequency of the monitoring signal in a case that the frequency of the sensing vibration is lower than the frequency of the monitoring signal.