The influence of chemical etching and preliminary cathodic and anodic polarization on the stationary electrode potential of a Hg3In2Te6 electrode has been investigated in various acidic solutions with different pH-values. It is shown that In3+ ions govern the process of formation of a double electric layer at the interphase semiconductor/electrolyte for electrodes submitted to preliminary chemical etching and anodization, while Hg2+ ions play the leading role in a similar process occurring on the electrodes after cathodic polarization.