One of the most important parameters to compose supersymmetry is the mass of supersymmetric partner of the third generation quarks. Top squark mass lighter than 1 TeV is favored in theory, however the evidence of the top squark have not been indicated from the various searches in Run-1. Therefore, a wide range of scenarios with different mass splittings between the top squark, the lightest chargino and the lightest neutralino should be considered. The poster presents recent ATLAS results from searches for direct stop pair production, decaying to a bottom quark and the lightest chargino, using the proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector and corresponding to an integrated luminosity of 13.2 ${\rm fb^{-1}}$. In particular, new dedicated search was developed to cover compressed phase spaces between the top squark and the lightest chargino and the result greatly extended the LHC Run-1 exclusion limit.