Abderemane Morame The Absolute Continuity of the Spectrum of Maxwell Operator in a Periodic Media (34K, LaTeX 2e) ABSTRACT. We prove the absolute continuity of the spectrum of Maxwell operator in a periodic media. It comes from our proof, that the sel-adjoint operator, on square integrable vector field with zero divergent, $rot(a(x)rot(b(x).)$ is with only absolutely continuous spectrum.