The ATLAS Phase II Upgrade program is preparing the ATLAS detector for the period of the Long Shutdown 3 (2024-2026) and beyond for the so called High Luminosity LHC (HL-LHC) phase which should deliver the ultimate performance of the accelerator. The instantaneous luminosities are expected to reach levels of 5-7.5x10^34 cm^(-2)s^(-1) corresponding to unprecedented pile up environment of up to 200 simultaneous pp interactions per bunch crossing. The goal is to reach the final dataset of integrated luminosity of 3000 fb-1, multiplying the total LHC Run1-3 dataset by a factor of ten. The ATLAS Upgrade Physics program investigates the ultimate sensitivities for various processes such as Higgs self coupling constant estimation and rare process as well as SUSY and Standard Model Measurement predictions. The physics and assumed detector performance will be presented in the seminar in the light of the recently published ATLAS Phase-II Upgrade Scoping Document.