  We present the first results of the search for sub-MeV fermionic dark matter
absorbed by electron targets of Germanium using the 205.4~kg$\cdot$day data
collected by the CDEX-10 experiment, with the analysis threshold of 160~eVee.
No significant dark matter (DM) signals over the background are observed.
Results are presented as limits on the cross section of DM--electron
interaction. We present new constraints of cross section in the DM range of
0.1--10 keV/$c^2$ for vector and axial-vector interaction. The upper limit on
the cross section is set to be $\rm 5.5\times10^{-46}~cm^2$ for vector
interaction, and $\rm 1.8\times10^{-46}~cm^2$ for axial-vector interaction at
DM mass of 5 keV/$c^2$.
