Mohamed A., Parisse B. Construction BKW pour l'operateur de Dirac. Cas d'un potentiel periodique. (252K, uuencoded-tar-gzipped-html) ABSTRACT. In the first part of this work, we compute explicitly the principal symbol of a WKB solution of the Dirac operator along a planar Agmon geodesic starting from a non-degenerate ponctual well. In the second part, we apply this result to study the band spectrum of a periodic Dirac operator near the minimum of the potential, we construct a class of potentials where the multiplicity of the Floquet eigenvalues is 1.