The Borexino experiment started the data taking may 15th 2007. It is until now the only experiment able to detect in real time neutrino interactions below 2 MeV. This is due to the very high radio-purity reached by the detector, more than one order of magnitude better than the goal of the design. The detector allows the single fluxes of low energy solar neutrinos to be determined from all sources not previously studied: 7Be, pep, CNO and hopefully pp. Here the first measurement of the 7Be, obtained from the first 47.6 live days of data taking, is presented.