The flight calibration of the ECAL of AMS-02 on ISS

The Alpha Magnetic Spectrometer (AMS-02) is a Cosmic Ray (CR) detector installed on the International space Station (ISS) on May 19th, 2011. The large statistics of events collected and the high resolution of the detector allow a precision measurement of rare component of CR, like e− and e+, essential for the indirect search of Dark Matter. The key detector in such measurement is the Electromagnetic CALorimeter (ECAL), both for its discrimination capabilities and, more important, to accurately measure the particle energy. In this contribution the flight calibration of the energy scale will be reviewed