[en] The present work has been performed with purpose to determine the level of hydrogen stability of sintered SmCo₅ permanent magnets by means of accelerated tests, to study the effect of hydrogen on the magnetic and mechanical properties of the permanent magnets and to establish the criteria of hydrogenation level and the activation energy of this process. In addition, the effect of hydrogen on the properties of sintered SmCo₅ permanent magnets in specific conditions of exploitation and storage durability of instruments was studied