<p>Provided is a highly precise aligning device capable of correcting the eccentricity of a lens automatically by measuring the eccentric state. The aligning device comprises a lens moving unit (105) for moving the lens in an optical system, an interferometer (101) for measuring the aberration of the optical system including the lens, and a movement control unit (103) for deciding the eccentricity of the lens from the measured aberration of the optical system, to decide the movement of the lens so that the eccentricity of the lens may be zero, thereby to instruct the movement decided by the lens moving unit.</p>
