Composite current collector

A current collector effective for reductions in weight and thickness. The current collector produced by forming a conductive layer having a surface electric resistance not higher than 1.3 OMEGA /cm on the surface of a resin film and then forming an electrolytic plating layer having a thickness of at least 0.3 mu m per one side, characterized in that the surface electric resistance is not higher than 40 m OMEGA /cm after electrolytic plating and following expression is satisfied; Y1+Y2+Y3 ), Y2: weight of conductive layer (mg/cm ), and Y3: weight of plating layer (mg/cm ).