[en] We investigated the electronic structure of SmNiC₂ by using X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD). The XAS and MCD measurements were performed around Sm L_2,3-edges and Ni K-edge. The element selective magnetic hysteresis curves were measured around Sm L_2,3-edges and Ni K-edge. The XAS spectrum showed a single peak around Sm L_2,3-edges. The valence of Sm ions in SmNiC₂ is a little smaller than trivalent. The MCD signals were clearly observed around all absorption edges below the Curie temperature. We concluded that Ni atoms in SmNiC₂ have a finite magnetic moment by analyzing the spectrum at Sm L₃-edge. The shape of ESMH loops were different from the hysteresis loop measured by a SQUID magnetometer. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)