  Superconductivity has been found in RuN films obtained by reactive magnetron
sputtering. This is a novel member of the metal nitride superconductors family.
The critical temperature of the superconducting transition varies depending on
the substrate and ranges from 0.77 K to 1.29 K. The parameters of the crystal
lattice of superconducting films have been determined: the lattice is distorted
cubic with parameters $a = b = c = 4.5586$ \AA , $\alpha =\beta =\gamma
=87.96^\circ$. A zero temperature upper critical magnetic field $H_{c2}(0)$ and
the coherence length were found from the experimental data using WHH model.
$H_{c2}(0) = 2.3$ T- 4.1 T for different substrates and exceeds the upper
paramagnetic limit, as well as $\xi = 12$ nm. An s-wave single band energy gap
$\Delta(0) = 0.19$ meV was revealed by self-field critical current experiment
at temperatures down to 10 mK, $2\Delta /kT_c =5.5$ exceeding the BCS ratio
3.5.
