A capacitive sensor includes a semiconductor substrate, a fixed electrode serving as a first electrode formed on a surface of or in the semiconductor substrate, a structure formed on the semiconductor substrate to have a vibratable second electrode that is formed to be spaced from and opposed to the semiconductor substrate and from the fixed electrode serving as the first electrode, a sealing member serving as a first sealing member formed on the semiconductor substrate to be spaced from the structure, to cover the structure, and to have a through hole serving as a first through hole, and a movable electrode serving as a vibratable third electrode formed on the sealing member to block up the through hole, and to be spaced from and opposed to the movable electrode.