A heat-treated steel wire for springs which is coiled by cold working, can combine sufficient atmospheric strength with suitability for coiling, and has a tensile strength of 2,000 MPa or higher; and a spring-use steel for use in producing the steel wire therefrom. The heat-treated steel wire for high-strength springs is characterized by containing, in terms of mass%, 0.5-0.9% C, 1.0-3.0% Si, 0.1-1.5% Mn, 1.0-2.5% Cr, 0.15-1.0%, excluding 0.15% and 1.0%, V, and less than 0.005% Al, having a nitrogen content reduced to 0.007% or lower, further containing one or both of 0.001-0.01%, excluding 0.01%, Nb and 0.001-0.005%, excluding 0.005%, Ti, and having a tensile strength of 2,000 MPa or higher; It is further characterized in that in a microscopic examination concerning cementite carbide spheres and alloy carbide spheres, the proportion of that area in the surface being examined which is occupied by these spheres having a diameter of 0.2 [mu]m or larger in terms of equivalent-circle diameter is 7% or lower and the population of the spheres having a diameter of 0.2 [mu]m or larger in terms of equivalent-circle diameter is 1 or less per [mu]<2>;, and that the former austenite grain size number is not smaller than 10 and the residual austenite content is 5 mass% or lower.