By using the exact renormalization group formulation we prove perturba
tively the Slavnov-Taylor (ST) identities in SU(2) Yang-Mills theory.
This results from two properties: locality, i.e. the ST identities are
valid if their local part is valid; solvability, i.e. the local part
of ST identities is valid if the couplings of the effective action wit
h non-negative dimensions are properly chosen.