摘要： Plasmonic structures attract much interest because they present exotic properties in areas that are much smaller than a wavelength. They are attractive for different applications such as sensors, single molecule detection, near-field microscopy, enhanced Raman spectroscopy, etc. At optical frequencies, metals act as a dielectric with negative permittivity and they lose their conductivity and become dispersive and lossy. As plasmonic structures are dispersive materials wich have a complicate frequency response so it is more convenient to simulate electromagnetic processes using frequency domain numerical methods. In this paper Method of Auxiliary Sources are presented as a numerical technique for simulation. MAS is frequency domain numerical solver of electromagnetic fields, which needs less computer resources then other numerical methods.