An objective lens unit used for an optical pickup device is made up of a
plurality of lenses and has a numerical aperture (NA) not less than 0.7.
The lenses (1) and (2) are secured within a cylindrically-shaped lens
holder (3). The position of the lens(es) (2) other than one of the lenses
secured within the lens holder is set with the position of the one lens
(1) as reference.