In this paper we present a highly efficient reversible microtubular cell in both modes of operation. These devices can produce hydrogen from electricity and steam (Solid Oxide Electrolyser, SOE), and then use the stored hydrogen to generate electricity and heat (Solid Oxide Fuel Cell, SOFC), acting as a storage device for electrical energy. Evaluation of the performance of the cell in electrolysis mode as a function of the steam concentration supplied to the cathode is discussed. Superior performance was obtained at 950 ºC for electrolysis operation. At 1.5V, we have obtained a current density of -2.95 A/cm2 using 70% H2O/ 15%H2 / 15%N2 as a fuel, with a total internal resistance of 0.26 ohm.cm2. The production of hydrogen in the electrolyser was also tested by mass spectrometry, confirming the high current efficiency for the steam electrolysis. These microtubular cells are very efficient and totally reversible, and especially in SOE mode where their performance is very promising for high temperature electrolysis applications.