  The HADES spectrometer installed at GSI Darmstadt is devoted to study the
production of di-electron pairs from proton, pion and nucleus induced reactions
at 1-2 AGeV. In pp collisions at 2.2 GeV we have focused mainly on exclusive
reconstruction of the $\eta$ meson decays in the hadronic
($\eta\to\pi^{+}\pi^{-}\pi^{0}$) and the electromagnetic channels ($\eta\to
e^{+}e^{-}\gamma$). We present analysis techniques and discuss first results on
$\eta$ production, with the main focus on comparisons of reconstructed
distributions to results obtained by other experiments and theoretical
predictions.
