Abstarct: Limited resources of fossil fuels and the increasing demand of energy would result in an energy crisis as the greatest worldwide problem in the near future. Using non-pollutant hydrogen fuel within a fuel cell is one of the most effective methods for energy generation. Electrolyte is an important part of a fuel cell which is mostly produced by tape casting method. Decreasing the thickness of electrolyte (i.e. increasing conductivity) is one of the most effective methods to increase efficiency and decrease the production cost of fuel cells. The raw material which is often used in manufacturing of electrolytes is yttria stabilized zirconia. It is shown from the previous researches that 3YSZ/8YSZ composites have high ionic conductivity and mechanical strength simultaneously. In this thesis, thin laxyers of zirconia baxsed solid electrolytes are produced by tape casting technique and process parameters were optimized. In the second step, Adding yttria to thin laxyers of 3YSZ was performed by means of net shape forming. Consequently, the mechanical properties such as hardness, elastic modulus, and fracture toughness were investigated by Micro-Vickers and Nano-Indentation methods. Micro Structure considerations were done by XRD and SEM tests. Electritical Conductivity was evaluated by Electrochemical Impedance Spectroscopy. Net shape formed sample had hardness of 13.34GPa, contact stiffness of 157.3µN/nm, Young's modulus of 258GPa, fracture toughness of 8.05MPa√m using Glandus equation and 8.41MPa√m using Blendell equation. Furthermore, Study of mechanical properties of zirconia baxsed electrolytes is one of unique aspects of this research.