Capacitive sensor

A capacitive sensor includes a fixed board provided with a fixed electrode unit consisting of one or more electrodes, a movable member provided with a movable electrode unit consisting of one or more electrodes which faces the fixed electrode unit with a gap therebetween, the movable member being rotatable with respect to the fixed board, a weight provided on the movable member, and a retaining element which is disposed between the fixed plate and the weight and retains the movable member in a rotatable manner. At least one of the movable electrode unit and the fixed electrode unit includes a plurality of electrodes.