The Ferricyanide-sensing electrodes were prepared with $Ag_2S;and;Ag_3Fe(CN)_6$ (mole ratio 3:1-7:1). The 5:1 $(Ag_2S:Ag_3Fe(CN)_6)$ composition is superior to others in terms of potentiometric response, rapidity of response and reproducibility. Testing was done over the concentration range $10^{-1}M{sim}10^{-6}M; Fe(CN)_6^{3-}$ at pH 6.8 with constant ionic strength. The concentration-potential curve was linear and coincided with the Nernstian slope (19.7 mV/decade). Interfering ions were $I^-,;Br^-,; SCN^-;and;Fe(CN)_6^{4-}$ and the life time of this electrode was 3 weeks. This electrode could be used as the indicator electrode for measuring the ferricyanide and ferrocyanide.