A displacement amount monitoring electrode structure comprising: a substrate, a detection mass (16; 18), a fixed electrode and a movable electrode, wherein each electrode has a comb-teeth shape including a base part (40; 50) and electrode fingers (42; 52) extending from the base part (40; 50) in a predetermined axis direction parallel to the substrate, the fixed electrode and the movable electrode facing each other such that the electrode fingers of the fixed electrode and the electrode fingers of the movable electrode are meshed together, and the fixed electrode being fixed to the substrate and the movable electrode being able to be displaced in the predetermined axis direction, wherein the displacement amount monitoring electrode structure is configured to monitor a displacement amount of the detection mass (16; 18) driven at a target amplitude, based on a change amount of a capacitance between the fixed electrode and the movable electrode, wherein a change sensitivity of the change amount of the capacitance with respect to a displacement amount of the movable electrode in the predetermined axis direction has a characteristic of increasing after the displacement of the movable electrode in the predetermined axis direction reaches a target displacement amount corresponding to the target amplitude, compared to before the displacement of the movable electrode reaches the target displacement amount, characterized in that the change sensitivity of the change amount of the capacitance with respect to the displacement amount of the movable electrode from a neutral position in one way of the predetermined axis direction, and the change sensitivity of the change amount of the capacitance with respect to the displacement amount of the movable electrode from the neutral position in another way of the predetermined axis direction, both have the characteristic. a substrate, a detection mass (16; 18), a fixed electrode and a movable electrode, wherein each electrode has a comb-teeth shape including a base part (40; 50) and electrode fingers (42; 52) extending from the base part (40; 50) in a predetermined axis direction parallel to the substrate, the fixed electrode and the movable electrode facing each other such that the electrode fingers of the fixed electrode and the electrode fingers of the movable electrode are meshed together, and the fixed electrode being fixed to the substrate and the movable electrode being able to be displaced in the predetermined axis direction, each electrode has a comb-teeth shape including a base part (40; 50) and electrode fingers (42; 52) extending from the base part (40; 50) in a predetermined axis direction parallel to the substrate, the fixed electrode and the movable electrode facing each other such that the electrode fingers of the fixed electrode and the electrode fingers of the movable electrode are meshed together, and the fixed electrode being fixed to the substrate and the movable electrode being able to be displaced in the predetermined axis direction, wherein the displacement amount monitoring electrode structure is configured to monitor a displacement amount of the detection mass (16; 18) driven at a target amplitude, based on a change amount of a capacitance between the fixed electrode and the movable electrode, wherein a change sensitivity of the change amount of the capacitance with respect to a displacement amount of the movable electrode in the predetermined axis direction has a characteristic of increasing after the displacement of the movable electrode in the predetermined axis direction reaches a target displacement amount corresponding to the target amplitude, compared to before the displacement of the movable electrode reaches the target displacement amount, characterized in that the change sensitivity of the change amount of the capacitance with respect to the displacement amount of the movable electrode from a neutral position in one way of the predetermined axis direction, and the change sensitivity of the change amount of the capacitance with respect to the displacement amount of the movable electrode from the neutral position in another way of the predetermined axis direction, both have the characteristic.