In this work, we investigate the PerfectlyMatched Layers (PML) introduced by Bérenger [3] for designing efficient numerical absorbing layers in electromagnetism.We make a mathematical analysis of this model, first via a modalanalysis with standard Fourier techniques, then via energytechniques. We obtain uniform in time stability results (that makeprecise some results known in the literature) and state some energydecay results that illustrate the absorbing properties of themodel. This last technique allows us to prove the stability of theYee's scheme for discretizing PML's.
