This chapter summarizes the ability of the ATLAS Detector at the CERN LHC to search for SUSY and make precision measurements of SUSY if it is discovered. The focus is on detailed studies of selected points in the minimal supergravity model, the minimal gauge mediated SUSY breaking model, and R-parity violating models. The chapter discusses the hierarchy problem, the role of SUSY in solving it, and the structure of the Minimal Supersymmetric Standard Model (MSSM). It describes the particle content of the MSSM, the interactions of SUSY particles, and the implications of SUSY breaking. The chapter also covers the Minimal Supergravity (SUGRA) model, including the parameters and the effects of SUSY breaking. It discusses the implications of R-parity violation and the different SUSY models, such as Gauge Mediated Supersymmetry Breaking (GMSB) and R-parity violating models. The chapter also addresses the detection of SUSY particles at the LHC, the challenges in distinguishing SUSY from the Standard Model, and the methods used to study SUSY processes. The chapter concludes with an overview of the different SUSY models and their implications for the LHC experiments.This chapter summarizes the ability of the ATLAS Detector at the CERN LHC to search for SUSY and make precision measurements of SUSY if it is discovered. The focus is on detailed studies of selected points in the minimal supergravity model, the minimal gauge mediated SUSY breaking model, and R-parity violating models. The chapter discusses the hierarchy problem, the role of SUSY in solving it, and the structure of the Minimal Supersymmetric Standard Model (MSSM). It describes the particle content of the MSSM, the interactions of SUSY particles, and the implications of SUSY breaking. The chapter also covers the Minimal Supergravity (SUGRA) model, including the parameters and the effects of SUSY breaking. It discusses the implications of R-parity violation and the different SUSY models, such as Gauge Mediated Supersymmetry Breaking (GMSB) and R-parity violating models. The chapter also addresses the detection of SUSY particles at the LHC, the challenges in distinguishing SUSY from the Standard Model, and the methods used to study SUSY processes. The chapter concludes with an overview of the different SUSY models and their implications for the LHC experiments.