The light adjustment apparatus of the present embodiment comprises a light adjustment part, a rotation axis body that supports a rotation arm that places and removes the light adjustment part in and out of a light path by swinging, and has a magnet installed therein, an electromagnetic drive source that forms a magnetic circuit including the rotation axis body on the circuit, and works an electromagnetic force on the magnet to rotate a rotational axis of the rotation axis body, and a float prevention part that magnetically restricts the rotation axis body, and prevents the rotation axis body from floating towards an axial direction of the rotational axis when the rotation axis body is rotated.
