The aim of the present work was to study the influence of the stress on the electrode potential of the austenitic stainless steel 301LN using Scanning Kelvin Probe (SKP). It was found that elastic deformation reversibly ennobles the potential whereas plastic deformation decreases the potential in both tensile and compressive deformation mode and this decrease is retained even 24 h after removal of the load. To interpret the stress effects, different surface preparations were used and the composition and thickness of the passive film were determined by GDOES. Slip steps formed due to plastic deformation were observed using AFM. The effect of plastic strain on the potential is explained by the formation of dislocations, which creates more a defective passive film.