  Muon tomography is a generic imaging method using the differential absorption
of cosmic muons by matter. The measured contrast in the muons flux reflects the
matter density contrast as it does in conventional medical imaging. The
applications to volcanology present may advantadges induced by the features of
the target itself: limited access to dangerous zones, impossible use of
standard boreholes information, harsh environmental conditions etc. The
Diaphane project is one of the largest and leading collaboration in the field
and the present article summarizes recent results collected on the Lesser
Antilles, with a special emphasis on the Soufri\`ere of Guadeloupe.
