  We construct a bosonization of the quantum superalgebra $U_q(\hat{sl}(N|1))$
for an arbitrary level $k$. We construct the screening that commutes with the
quantum superalgebra for an arbitrary level $k \neq -N+1$. We propose a
bosonization of the vertex operator that gives the intertwiner among the
Wakimoto realization and the typical representation.
