Wherever the electron beam interacts with gas e.g. in gaseous lasers or plasma chemical reactors, currents and spatial charges induced in plasma play an important role in the course of processes. They decide about magnetic compensation and electrostatic fields, so they influence the electrons heating, development or suppression of instabilities and thus on the beam transport, additional ionization, selectivity of energy deposition etc. This paper includes results of investigations of some aspects of plasma currents dynamics in often used gases: Ar and molecular one - air.