Résumé : The cross section ratio of the elastic neutral current reaction νp→νp to the quasi-elastic charged current reaction νn→μ-p has been measured in the kinematical region 0.3≤q2≤1.0 (GeV/c)2. The measured value is RM=0.17±0.08. Model dependent corrections are applied, especially for νn→νn contamination, and the result is compared to various models. © 1978.