An optical pickup apparatus comprises: a first light source for emitting a
first light flux; a second light source for emitting a second light flux;
a third light source for emitting a third light flux; and an objective
optical element. The objective optical element comprises an optical
surface comprising a central area and a peripheral area. The central area
comprises a first optical path difference providing structure, and the
peripheral area comprises a second optical path difference providing
structure. The objective optical element converges the third light flux
which passes through the central area of on the third optical disk. The
objective optical element converges the first and second light fluxes
which pass through the peripheral area on the first optical disk. Each of
the first and second optical path difference providing structures
comprises a predetermined basic structure.