A steel for high-strength springs contains, on the mass basis, 0.35% to
0.65% of C, 1.4% to 2.5% of Si, 0.1% to 1.0% of Mn, 2.0% or less
(exclusive of 0%) of Cr, 1.0% or less (exclusive of 0%) of Ni, 1.0% or
less (exclusive of 0%) of Cu, 0.020% or less (exclusive of 0%) of P,
0.020% or less (exclusive of 0%) of S, 0.006% or less (exclusive of 0%)
of N:, and 0.1% or less (exclusive of 0%) of Al, with the remainder being
iron and inevitable impurities, in which Wp(Fe) and W(C) satisfy the
following condition: Wp(Fe)>5.times.W(C), wherein Wp(Fe) is the
content of Fe (percent by mass) constituting Fe-containing precipitates
in the steel; and W(C) is the carbon content (percent by mass) of the
steel. The steel is excellent in cold workability and quality stability.