According to this lens-centering method, a state in which a lens (7) is sandwiched at prescribed pressing force between a lens holder (4) and a lens processing dish (8) is brought about (steps ST1-3). Next, the lens-processing dish (8) is rotated at slow speed about a rotation axis line (8A) that passes through the center (C(8a)) and the spherical center (O(8a)) of the lens-processing surface (8a) thereof, and is made to oscillate at a slight angle about the spherical center (O(8a)) of the lens-processing surface (8a) as the center of oscillating action. The spherical center of a first lens spherical surface (7a) of the lens (7) is guided to the spherical center of a lens-retaining surface (4a) of the lens holder (4), and the spherical center of a second lens spherical surface (7b) is guided to the spherical center 8(C(8a)) of the lens-processing surface (8a) (rotation/oscillation step ST4). A lens mounted in the spherical center-type processing machine can be set to an accurately centered state thereby.
