  This paper presents a study of the performance of the muon reconstruction in
the analysis of proton-proton collisions at $\sqrt{s}$=7 TeV at the LHC,
recorded by the ATLAS detector in 2010. This performance is described in terms
of reconstruction and isolation efficiencies and momentum resolutions for
different classes of reconstructed muons. The results are obtained from an
analysis of J/$\psi$ meson and Z boson decays to dimuons, reconstructed from a
data sample corresponding to an integrated luminosity of 40~$pb^{-1}$. The
measured performance is compared to Monte Carlo predictions and deviations from
the predicted performance are discussed.
