In this study, the electrochemical behavior of 304L SS stainless steel in various nitric acid/chloride ratios was investigated. The characteristics of the passive film, formed at the open circuit potential (OCP) and at the passive potential (0.65 V vs SCE) were also compared. OCP results show that a stable passive film formed over the surface with higher nitric acid/chloride ratios. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurements showed that with higher nitric acid/chloride ratios, the film resistance increases ( R 1 ) for OCP, passive potential, and the critical current density ( i crit ) and corrosion rate ( i corr ) decreases. Mott–Schottky analysis revealed that the film formed at OCP shows n-type behavior for 0.01 N and 1 N concentration and shows p-type behavior for 0.1 N nitric acid concentration. At 0.65 V (vs. SCE) of film formation potential, the film formed in 1 N concentration shows n – type behavior. In 0.01 N and 0.1 N acid concentration, p-type behavior has been observed. Also, according to Mott–Schottky analysis, it was found that a lower defect density was found in 0.1 N nitric acid, for both the potentials. X-ray photoelectron spectroscopy spectra show evidence that the surface contains Fe and Cr as major elements. However, at OCP, Fe 2 O 3 was the main constituent of the passive film, whereas the passive potential film was rich in Cr 2 O 3 . In addition, nitrogen and chloride were adsorbed in the passive film at passive potential.