We successfully demonstrated SPECTRAL’s LIBS sensor 150 meters below the surface in an old silver mine. We showed that our LIBS sensor equipment is robust and transportable for operation down in the mine and that it delivers high quality LIBS signals in this harsh environment. Examples: we detected sulphur at 180.7 nm and trace levels of silver.  Although the Reiche Zeche mine in Freiberg (Germany) is not operational anymore, the conditions are comparable to a real operational environment. This is another step in or ambition to bring laboratory equipment to mining operations. (Work performed as part of the EU H2020 project “Real-Time Mining”)