  The total set of the neutrino - electron processes in a presence of both
components of an active medium, hot dense plasma and strong magnetic field, is
investigated for the first time. The contribution of the processes $\nu e^- \to
\nu e^-$, $\nu e^+ \to \nu e^+$, $\nu \to \nu e^- e^+$, $\nu e^- e^+ \to \nu$
is shown to dominate and not to depend on the chemical potential of
electron-positron gas. Relatively simple expressions for the probability and
mean losses of the neutrino energy and momentum are obtained, which are
suitable for a quantitative analysis.
