A optical system radial deformation adjustment method includes predicting radial deformation generated when an optical system comprising at least an optical element is assembled, calculating a surface shape and a change quantity of the optical element that are used to correct the predicted radial deformation, applying correction processing to the surface of the optical element based on the calculated surface shape and change quantity of the optical element, and assembling and adjusting the optical system by using the optical element to which the correction processing is applied as the optical element from which the radial deformation is predicted.