The paper presents the results of determination of the ore contents of rare earth elements (REE) in geological samples by atomic emission spectrometry with arc two-jet plasmatron, which allows to analyze solid-phase samples as a fine powders. We studied a niobium-rare earth ore sampled at the Buranniy site of the Tomtor deposit (Arctic Siberia, Russia). The results for all REEs, except for Tb, Yb and Lu, are consistent with the ICP-MS data. It is shown that the use of several analytical lines at the same time in the determination of REE significantly increases the determination accuracy and reliability of the results.