A lens device is provided and includes: a lens barrel body; a lens frame swingably attached to the lens barrel body; and a swing mechanism being adapted to swing the lens frame so that alignment of an optical axis of the lens device can be effected, the swing mechanism including: an elastic unit interposed between the lens barrel body and the lens frame, the elastic unit biasing the lens barrel body and the lens frame in directions away from each other or in directions nearing to each other; and an advancing and retracting unit disposed at three points in a circumferential direction defined by the lens barrel body and the lens frame, the advancing and retracting unit advancing or retracting the lens frame relative to the lens barrel body against a bias force of the elastic unit to swing the lens frame.