Bulk Er123 (ErBa2Cu3O7-δ) superconducting ceramics were prepared via conventional solidstate reaction. The samples were subjected to thermal treatment for 24 h calcined at 1223 K. The pelletized powder was sintered at 1223 K for 24 h. The samples showed a single step transition in the resistivity versus temperature curves. The Tconset of the samples was 93 K. The XRD data showed thatthe superconducting compound had an orthorhombic structure with the lattice constant asa = 3.82Å, b = 3.88 Å, c = 11.68 Å and orthorhombicity parameter as 1.69% whereas the non – superconducting compound was a cubic structure with a = b = c = 18.25Å. The simulation of atomic position in three dimensions. The SEM micrographs showed large grain sizes with a homogeneous surface. The EDX (mapping) showed a smooth distribution of Er, Ba, Cu and O bands without impurities. The heat reaction showed the endothermic curve with the peritectic temperature at 1277.980K carried out by the DTA technique. Finally, The Cu2+= 6.30×10−6 and Cu3+= 1.82 ×10−6Cu3+/Cu2+= 0.29 and oxygen deficiency have a δ value of 0.16 which were determined by a standard iodometric titration method.