A projection objective includes a first lens group (G1) of positive refractive
power, a second lens group (G2) of negative refractive power and at least
one further lens group of positive refractive power in which a diaphragm is mounted.
The first lens group (G1) includes exclusively lenses of positive refractive
power. The number of lenses of positive refractive power (L101 to L103;
L201, L202) of the first lens group (G1) is less than the
number of lenses of positive refractive power (L116 to L119; L215
to L217) which are mounted forward of the diaphragm of the further lens
group (G5).