To provide a steel wire material which is excellent in adhesiveness to a covering rubber and also in wire drawability.

A brass plating layer 12 which is formed on the peripheral surface of a wire body 11 of the steel wire material 10 is made into a composite plating structure, also the alloy layers 21-28 (the first layer to the eighth layer) on the side of the wire body 11 are made into high Cu-layers (the composition rate of Cu; 65-75 wt.%) which are good in workability (wire drawability) and the alloy layers 31-34 (the ninth layer to the twelfth layer) on the side of the surface are made into low Cu-layers (the composition ratio of Cu; 50-60 wt.%) which are good in adhesion durability.