\documentstyle[11pt]{article} \begin{document} \title{ Coupling of finite and boundary element methods for the transmission problem for the time-harmonic Maxwell equations} \author{ H. Ammari} \address{Center of Applied Mathematics, CNRS UMR 7641, Ecole Polytechnique\\ 91128 Palaiseau Cedex, France\\ E-mail: ammari@cmapx.polytechnique.fr} \author{ J.-C. N\'ed\'elec} \address{Center of Applied Mathematics, CNRS UMR 7641, Ecole Polytechnique\\ 91128 Palaiseau Cedex, France\\ E-mail: nedelec@cmapx.polytechnique.fr} \maketitle \begin{center} {\bf Abstract} \end{center} We describe and analyze a method for computing an approximation to the time-harmonic electromagnetic field scattered by a bounded dielectric material surrounding a metallic body. The method is to couple a finite element scheme on the dielectric medium with an integral equation on its boundary. By proving that a saddle point structure holds for the continuous as well as the discretized problem, we extend the error estimates proved by Bendali for the scattering problem by a conducting object to the more general problem of electromagnetics, where we also have dielectric and metallic objects. Our method is based on the use of a Hodge decomposition of the electric field and a new integral representation formula for the tangential component of the magnetic field on the boundary of the dielectric medium. \end{document}