Synopsis We present a new approach to describe electronic processes occuring in ion-atom and ion-molecule collisions at impact energies ranging from 50 eV.u-1 to 500 keV.u-1.The treatment is based on the semiclassical approximation in which the time-dependent Schr(o)dinger equation is solved non perturbatively, taking into account all the electrons of the collision systems.This allows to describe exactly multielectronic processes and also, at the same footing, processes involving valence and inner shell electrons.