  A gauge invariant Wilsonian effective action is constructed for pure SU(N)
Yang-Mills theory by formulating the corresponding flow equation. Manifestly
gauge invariant calculations can be performed i.e. without gauge fixing or
ghosts. Regularisation is implemented in a novel way which realises a
spontaneously broken SU(N|N) supergauge theory. As an example we sketch the
computation of the one-loop beta function, performed for the first time without
any gauge fixing.
