To provide a ceramic which exhibits high strength when it is baked and from which a paste, which hardly reacts with zirconia and/or an electrode material and can be baked at a relatively low temperature, can be prepared, an electrochemical element wherein the ceramic is used as a reaction inhibiting layer, a method for manufacturing the same, and a fuel cell and an apparatus for concentrating oxygen, obtained by using the electrochemical element.

The ceramic contains Ce(1-x)LnxO2-δ (wherein, Ln is one of rare earth elements except Ce, x is >0 and ≤0.30, and δ means oxygen defect and a number required for neutralizing the electric charge in the compound) and at least one kind of metal selected from Co, Mn, Ni, Cu and Fe. The electrochemical element has a zirconia-based solid electrolyte base material, an anode and a cathode. In the electrochemical element, the reaction inhibiting layer formed from the ceramic is provided between the zirconia-based solid electrolyte base material and the material forming the cathode. The method for manufacturing the electrochemical element is also provided. The fuel cell and the apparatus for concentrating oxygen are obtained by using the electrochemical element.