The modification of surface properties resulting from H2S adsorption on a fully sodium-exchanged Y zeolite was studied in situ using a combination of Infrared and Solid-State NMR spectroscopy. In order to perform in situ measurement in the same conditions with both techniques, a homebuilt device for preparing the NMR samples under vacuum or controlled atmosphere was used. Double-resonance NMR methods were achieved for a complete assignment of the different lines in proton NMR spectra. A small fraction of H2S is shown to adsorb dissociatively on NaY whereas the main part of H2S interacts non-dissociatively, either by coordination with the Na+ cations or by H-bonding.