The electrochemical behavior of ferritin at the polarized water|1,2-dichloroethane (DCE) interface was studied, mainly under acidic conditions. No obvious voltammetric responses were observed under neutral and alkaline conditions where ferritin formed an uncharged nanocage structure. On the other hand, large electrochemical responses were obtained in the positive potential region under acidic conditions where ferritin was disassembled into positively charged subunits. These responses varied slightly with the concentration of the supporting electrolyte in the organic phase and changed drastically with the concentration of ferritin and under repetitive sweeps. In addition, depending on the applied potential and the concentration of ferritin, a white film was formed at the interface. This electrochemical behavior could be attributed to ion transfer and the adsorption/desorption of positively charged ferritin subunits with the interfacial activity accompanied by the facilitated ion transfer of the organic supporting electrolyte anion.