The composition of oxide layers that grow under air exposure at room temperature on the surface of SnTe monocrystals was studied by Raman spectroscopy, angle resolved X-ray photoelectron spectroscopy (ARXPS), and Time Of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS). It is established that a multilayered structure with a non-uniform depth distribution of components is formed. The main components of this structure are tin dioxide SnO2 and tellurium in three chemical states-elementary Te, tellurium dioxide TeO2 and tellurium suboxide TeOx (0 < x < 2). The kinetics of oxidation studied in a range from 10 min to 2 years demonstrates that SnTe oxidation at room temperature is a prolonged process. The comparison of TOF-SIMS spectra obtained for SnTe and PbTe shows that this process is much faster in SnTe than in PbTe. Environmental susceptibility of SnTe surface proved by our experiments requires particular attention to ensure the manufacture and application of quality topological crystalline insulator-based devices made of SnTe. (C) 2018 Elsevier B.V. All rights reserved.