Résumé : The q2 variation of the factor f{hook}+(q2) in the decay K+→π0e+ν has been studied using a sample of even detected in the CERN 1.1 m3 heavy-liquid bubble chamber. The data are consistent with a linear development f{hook}+(q2)=f{hook}+(0) (1+λ+q/m2π) with λ+=0.027±0.008. © 1973.