According to this lens-centering method, a state in which a lens is sandwiched at prescribed pressing force between a lens holder and a lens processing dish is brought about. Next, the lens-processing dish is rotated at slow speed about a rotation axis line that passes through the center and the spherical center of the lens-processing surface thereof, and is made to oscillate at a slight angle about the spherical center of the lens-processing surface as the center of oscillating action. The spherical center of a first lens spherical surface of the lens is guided to the spherical center of a lens-retaining surface of the lens holder, and the spherical center of a second lens spherical surface is guided to the spherical center of the lens-processing surface. A lens mounted in the spherical center-type processing machine can be set to an accurately centered state thereby.
