  \noindent Let $\mu(f)$ resp. $c(f)$ be the Milnor number resp. the degree of
the conductor of an irreducible power series $f\in \bK[[x,y]]$, where $\bK$ is
an algebraically closed field of characteristic $p\geq 0$. It is well-known
that $\mu(f)\geq c(f)$. We give necessary and sufficient conditions for the
equality $\mu(f)=c(f)$ in terms of the semigroup associated with $f$, provided
that $p>\ord f$.
