Let f : C n ! C be a polynomial function. We deene global polar invariants associated to bres of f and we describe a CW-complex model of a bre. We show how to use aane polar curves in order to study the monodromy around atypical values of f, including the value innnity. We give a zeta-function formula for such a monodromy. Topologie des fonctions polynomiales et dynamique mono-dromique R esum e...