The new center for geochronology at the University of Geneva needed to purchase a new thermal ionization mass spectrometer of the last generation. This new instrument offers on one hand new analytical options not available on our old MAT262 mass spectrometer, and on the other hand higher precision in both multicollection mode and single-collector, ion-counting mode. The decision was taken for a Triton from Thermo Fisher Scientific (Bremen). The current research is focussed on Sr, Nd, Pb tracing of magmatic rocks, as well as high-precision U-Pb dating of smallest amounts of zircon, using the new, linear, discrete-dynode MasCom electron multiplier in ion pulse counting mode. This equipment can yield 206Pb/238U ages with sub-permil precisions, needed for the precise and quantitative investigation of geological and biotic events in the histrory of the Earth.