  MIMAC (MIcro-TPC MAtrix of Chambers) is a directional WIMP Dark Matter
detector project. Direct dark matter experiments need a high level of
electron/recoil discrimination to search for nuclear recoils produced by
WIMP-nucleus elastic scattering. In this paper, we proposed an original method
for electron event rejection based on a multivariate analysis applied to
experimental data acquired using monochromatic neutron fields. This analysis
shows that a $10^5$ rejection power is reachable for electron/recoil
discrimination. Moreover, the efficiency was estimated by a Monte-Carlo
simulation showing that a 105 electron rejection power is reached with a
$86.49\pm 0.17$\% nuclear recoil efficiency considering the full energy range
and $94.67\pm0.19$\% considering a 5~keV lower threshold.
