Résumé : Candidates for the purely leptonic process νμe-→νμe- have been searched for in the bubble chamber Gargamelle exposed to the CERN-SPS antineutrino wide-band beam. No single e-, of energy greater than 1 GeV, was found in a total of 230 000 pictures, corresponding to 7400 charged current events. This leads to an upper limit for the observed cross section of σobs < 1.6 × 10-42 ( Eν- GeV) cm2 (90% C.L.). Interpretation of this value in terms of the standard W Weinberg-Salam model yields an upper limit to the mixing parameter sin2θW < 0.39 at 90% C.L. © 1979.