  Invariant integrals on Hopf superalgebras, in particular, the classical and
quantum Lie supergroups, are studied. The uniqueness (up to scalar multiples)
of a left integral is proved, and a super version of Maschke's theorem is
discussed. A construction of left integrals is developed for classical and
quantum Lie supergroups. Applied to several classes of examples the
construction yields the left integrals in explicit form.
