  We report superconductivity with $T_{c,onset}$=$\sim$10K in
Pr$_{2}$Ba$_{4}$Cu$_{7}$O$_{15-\delta}$ compound possessing metallic double
chains. A reduction treatment on as-sintered samples causes not only the
enhanced metallic conduction but also the appearance of superconductivity
accompanied by the c-axis elongation due to oxygen deficiency.
