Аннотация:One of promising materials for creating highly sensitive and selective gas sensors of the resistivetype is nanocrystalline zinc oxide . At present, zinc oxide (ZnO) with various impurities is mainlystudied, the significant advantage of which is the possibility of controlling the electrophysicalproperties in a wide range . Thus, for example, acceptor impurities (N, P, As, Sb) are used toobtain ZnO of the hole type of conductivity, and donor impurities (Al, In, Ga) are used to increase theelectron concentration . Currently, there is no single point of view on the processes that determinethe mechanisms of electrical conductivity and gas sensitivity of ZnO and materials based on it. Theabsence of a specific theory, describing of electron possesses in ZnO, is an obstacle to the furtherdevelopment of sensor devices based on this oxide. To build a general model, it is important to studythe type, properties, and peculiarities of spin centers in the ZnO structure, since they are responsiblefor the change in conductivity as a result of surface reactions. The aim of this work was to study thespin centers in the samples of nanocrystalline zinc oxide depending on the synthesis conditions.