ATLAS detector performances for electrons and photons

We review in this document the performances of the ATLAS detector for the identification of the electrons and photons as well as for the reconstruction of their properties. The determination of the electromagnetic energy scale with proton-proton collision data is presented. The procedure to identify electrons and photons is described as well as the measurement of the efficiency of this procedure with proton-proton collision data. The concept of isolation and an example of its usage in the ATLAS research programme is presented.