A nanometer-sized porous metallic glass and a method for manufacturing the same are provided. The porous metallic glass includes Ti (titanium) at 50.0 at % to 70.0 at %, Y (yttrium) at 0.5 at % to 10.0 at %, Al (aluminum) at 10.0 at % to 30.0 at %, Co (cobalt) at 10.0 at % to 30.0 at %, and impurities. Ti+Y+Al+Co+the impurities=100.0 at %.