An external magnet provided outside a sealed container is movable with respect to the sealed container, and an external member moves the external magnet. An internal magnet provided in the sealed container is movable with respect to the sealed container, and an internal member is moved by movement of the internal magnet. The external magnet and the internal magnet are arranged in such a manner that the internal magnet is moved by the action of a repulsive force between the external magnet and the internal magnet based on movement of the external magnet.