To provide an acceleration sensor easily absorbing the offset of a sensor output and its fluctuation according to the operating environment, suppressing the increase of chip size.

A first moving part 11 having a specific displacement direction is floatably supported to a substrate 10. A second moving part 12 having the displacement direction is supported to the first moving part 11. To the first and the second moving parts 11 and 12 (structure bodies), an alternating current signal from an alternating current source 31 is input. A signal corresponding to the charge accumulated in a capacitor formed between the first moving part 11 and a fixed electrode 14a based on the alternating current signal is input from the fixed electrode 14a to a first detection circuits 32 and the like, and the displacement of the first moving part 11 against the substrate 10 is detected. Similarly, the displacement of the second moving part 12 against the substrate 10 is detected. To the fixed electrode 14a, a servo voltage is supplied so that electrostatic attraction suppressing the displacement is caused based on the detected displacement of the first moving part 11.