A capacitive acceleration sensor is composed of a silicon plate, a glass plate and a substrate. The silicon plate has a fixed portion and a movable portion supported by the fixed portion through spring beams. The movable portion is moved in response to the change in the acceleration and is provided with a moving electrode thereon. The glass plate is provided with a fixed electrode and anodically bonded to the silicon plate so that the fixed electrode faces the moving electrode with a predetermined gap. On the glass plate, a first dummy electrode is formed at a location corresponding to the spring beams of the silicon plate. The dummy electrode has a terminal portion at one end so as to be electrically connected with the silicon plate during anodic bonding of the plates. On the substrate, a second dummy electrode is formed at a location corresponding to the movable portion of the silicon plate. The dummy electrode, similarly, has a terminal portion at one end so as to be electrically connected with the silicon plate during anodic bonding of the silicon plate and the substrate.