The article presents the results of mass-spectrometric studies of changes in the composition of the air environment in the restoration area of worn-out working parts' surfaces obtained using a monopole gas mass spectrometer МХ7304. The restoration of worn working parts' surfaces was carried out by the traditional method of electric arc welding by surfacing in a protective argon environment on steel 12Х18Н10Т wearresistant coating with OK61.30 grade electrodes. The electrospark alloying method was also used using the Elitron-52A installation. As a result of the studies, it was found that no toxic gases appear in the composition of the air in the area of electrospark alloying. At the same time, the presence of a large amount of carbon dioxide CO2 and unstable nitric oxide NO was found in the composition of the air in the area of electric arc welding. Both of these gases are toxic even in small quantities. On the basis of the experimental results obtained, a conclusion was made about the environmental safety of the method of electric spark alloying in the restoration of worn working parts' surfaces in comparison with the traditional method of electric arc welding.