The « Mass Spectrometry – Nuclear Spectrometry » platform offers a state-of-the-art service in the field of elemental and isotopic analysis of geological samples for LMV researchers as well as collaborators from national and international institutions. It provides over-pressurized clean rooms, dedicated to the different methods and are equipped with laminar air flow fume hoods. This is to ensure that the chemical treatment and separation of the elements of interest from geological samples are compatible with mass spectrometry analysis. The equipment available to date includes a multi-collection plasma source mass spectrometer MC-ICPMS Thermo Neptune plus, two Thermo Triton TIMS thermo-ionization mass spectrometers. All these equipments allow the analysis of isotopic systems with long period radioactivity, extinguished radioactivity and systems of non-traditional stable isotopes. The platform is also equipped with an ICP-MS Thermo Element XR spectrometer, and an Agilent 7500 quadrupole ICP-MS spectrometer coupled with a 193 nm Resonetics Excimer laser ablation device that allows point analysis on separate minerals embedded in epoxy resin cylinders and on thin polished slides. In the field of in situ U-Th-Pb geochronology, we welcome and supervise researchers and PhD students from the main French research centers in Earth Sciences, as well as researchers and engineers from Germany, Italy, Belgium, Spain, United States etc. In order to measure the very short-lived radioactive imbalances (resulting from the natural decay of uranium and thorium) of recent lava and volcanic gases in relation to eruptive activity, the laboratory has a well y spectrometer, a spectrometer α and a global counter α-β. The latter will soon be replaced by new equipment.