The level of density fluctuations is shown to decrease during ergodic divertor operation in Tore Supra. This decrease of the turbulence is correlated with the onset of a temperature pedestal and a local improvement of the confinement. This pedestal is located close to the electric shear layer, i.e. within a narrow region between the plasma core and the ergodic layer. The onset of such a pedestal explains why the central electron temperature is not changed when the ergodic divertor is switched on, in spite of an ergodic zone where the temperature is low