Abstract: For the construction of an all-solid state fluoride electrode it is necessaryi to find a suitable inner solid state junction between the ion-conducting LaF₃membrane and the electron-conducting metalic lead.In order to achleve a good electrode quality, it is essential to get a non-blocking, ohmic contact. Various fluorides and/or metals have been deposited on the LaF₃ crystal membrane using' vacuum evaporation method: Bi (A);B₁ (B);BiF₃-Bi-Ag(B₁); Pb(C) ;PbF₂-Pb(D);Ag(E);AgF-Ag(F);Au(G);Al(H). The electrochemical properties of the inner junctions have been tested by mea-suring current-voltage characteristics.That the contact obtained is an ohmic one is indicated by linear current-voltage relationship which is independent of the polarity. It has been shown that in systems of direct junction between a metal and LaF₃ crystalmembrane the contact resistance shows nonohmic behavior (Fig. 2, A, C, E, G, H). These blocking contacts also possess rectiflying properties.The contact can be made ohmic when a layer of ion-conducting fluoride(BiF₃, F₂ or AgF) is sandwiched in between the LaF₃ crystal membrane and the corresponding metal deposit layer (Bi, Pb or Ag; Fig.2,B,D, F) .The migration of fluoride ions in the LaF₃ membrane has been experimentally observed by electrolytic formation of fluorides of bismuth and lead on the LaF₃; crystal, membrape surface. The system B1 (BiF₃-Bi-Ag) is recommended as especially suitable for the construction of all-solid state fluoride electrodes.The potential resiponse characteristics of the constructed electrodes have been evaluated.