Dense beta ''-alumina electrolyte tubes with thickness less than 50 mu m were slip cast on a porous substrate of beta ''-alumina. The resistance of the composite electrolyte was measured by a DC method. The area specific resistance of a thin layer electrolyte versus the full thickness electrolyte was lower by a factor of 1.6. The components of cell resistance were determined. It was concluded that interfacial resistance is a dominant factor in the electrolyte resistance. (C) 2011 Elsevier B.V. All rights reserved.