  This paper gives an overview of a reconstruction algorithm for muon events in
ATLAS experiment at CERN. After a short introduction on ATLAS Muon
Spectrometer, we will describe the procedure performed by the algorithms
Muonbox and Muonboy (last version) in order to achieve correctly the
reconstruction task. These algorithms have been developed in Fortran language
and are working in the official C++ framework Athena, as well as in stand alone
mode. A description of the interaction between Muonboy and Athena will be
given, together with the reconstruction performances (efficiency and momentum
resolution) obtained with MonteCarlo data.
