  The importance of an adequate CNGS beam monitor at the Gran Sasso Laboratory
has been stressed in many papers. Since the number of internal $\nu_\mu$ CC and
NC interactions in the various detectors will not allow to collect statistics
rapidly, one should also be able to detect the $\nu_\mu$ CC interactions in the
upstream rock. In this study we have investigated the performances of the LVD
detector as a monitor for the CNGS neutrino beam. Thanks to its wide area ($13
\times 11 m^2$ orthogonal to the beam direction) LVD can detect about 120 muons
per day originated by $\nu_\mu$ CC interactions in the rock. The LVD total mass
is $\sim2 kt$. This allows to get 30 more CNGS events per day as internal $(NC
+ CC)$ $\nu_\mu$ interactions, for a total of $\sim 150$ events per day. A 3%
statistical error can be reached in 7 days. Taking into account the time
characteristics of the CNGS beam, the cosmic muon background can be reduced to
a negligible level, of the order of 1.5 events per day.
