A tracker consisting of 16 MSGCs has been installed in the high intens
ity muon beam of the SMC experiment[1] at CERN. Each MSGC has an activ
e surface of 10 x 10 cm(2), covered by 496 anode strips. As a front-en
d amplifier the APC 64 is used. Results are presented about the effici
ency, both at a high rate and at a low rate, and the position resoluti
on. Using the data of the MSGC tracker the definition of the beam trac
ks in SMC significantly improved.