  In the past decades, short baseline neutrino oscillation studies around
experimental or commercial reactor cores have revealed two anomalies. The first
one is linked to the absolute flux and the second one to the spectral shape.
The first anomaly, called Reactor Antineutrino Anomaly (RAA), could be
explained by the introduction of a new oscillation of antineutrinos towards a
sterile state of the eV mass. The \stereo detector has been taking data since
the end of 2016 at 10~m from the core of the Institut Laue-Langevin research
reactor, Grenoble, France. The separation of its Target volume along the
neutrino propagation axis allows for measurements of the neutrino spectrum at
multiple baselines, providing a clear test of an oscillation at short baseline.
In this contribution, a special focus is put on the data analysis and the
neutrino extraction using the Pulse Shape Discrimination observable. The
results from 119 days of reactor turned on and 210 days of reactor turned off
are then reported. The resulting antineutrino rate is (365.7~$\pm$~3.2) \anue
/day. The test of a new oscillation towards a sterile neutrino is found to be
compatible with the non-oscillation hypothesis and the best fit of the RAA is
excluded at 99\% C.L.
