In order that spaces, including a space in the central portion, inside a steel cord used as a reinforcement by being embedded in a tire or the like are filled with an uncured rubber, the uncured rubber is coated on plural steel core filaments which are then stranded to form a single layer steel cord, the core then being stranded with uncoated outer layer filaments. Consequently, it is possible to exhibit satisfactory corrosion resistance and satisfactory fatigue resistance as a steel cord, shorten a curing time in tire component assembling or the like to attain energy saving and prolong the life of a steel cord itself and the life of a tire or the like using the same as a reinforcement. Further, production can be performed at low cost.