The lens unit includes an imaging lens including lenses, each of which
includes a lens portion having an optical function and a flange portion
on a periphery of the lens portion, and a ring-shaped lens holding member
provided between the lenses and holds at least one of the lenses and a
cylindrical-shaped lens-barrel including a lens holding portion that
holds the imaging lens. The flange portion of each of the lenses is
fittable to the flange portion of the other lens of the lenses, or the
lens holding portion or an inner surface of the lens-barrel, and the
lenses combined with each other through fitting to the flange portion of
the other lens, the lens holding portion or the inner surface of the
lens-barrel have respective shapes in which optical axes of the lenses
coincide each other under a fitting state. The compact image pickup
module includes the lens unit.