Techniques capable of suppressing fixation between a movable electrode and a fixed electrode in an inertial sensor and preventing the inertial sensor from malfunctioning are provided. The movable electrode, the fixed electrode provided so as to face the movable electrode, a peripheral conductor facing both the movable electrode and the fixed electrode, and a demodulation circuit and a voltage adjustment circuit which adjust the electric potential of the peripheral conductor so that the electric potential of the peripheral conductor becomes the same as the electric potential of the movable electrode are provided, and a change in the capacitance between the movable electrode and the fixed electrode is detected.