A new superconducting double perovskite was successfully synthesized by a low-temperature hydro thermal reaction at 240 degrees C. The crystal structure refinement of this double perovskite was done by single crystal X-ray diffraction, and it had a cubic unit cell of a = 8.5207(2) angstrom with space group Im (3) over barm (No. 229). This superconducting double-perovskite chemical composition was estimated by electron probe microanalysis and was similar to the refined data. The superconducting transition temperature of the double perovskite was similar to 30 K; the electrical resistivity began to fall at similar to 25 K, and zero resistivity occurred below 7 K. Moreover, temperature dependent resistivity under various magnetic fields and isothermal magnetization measurements ensured the nature of a type II superconductor for the sample. Finally, the metallic nature of the material was investigated by a first-principles study.