An objective lens for use in an optical pickup apparatus for conducting recording
and/or reproducing information for an optical information recording medium, has
a lens section shaped in an approximate circle and including a flange section;
and a projecting section integrally provided to the lens section. The objective
lens satisfies the following conditional formulas:
0.5A2.0, 0.3AB1.7A
where A is a diameter (mm) of the lens section when the lens section is viewed
from an direction of an optical axis, and B is a width (mm) of the projecting section
when the connecting section is viewed from the direction of the optical axis.