A seamless steel pipe for a hollow spring, containing 0.2 to 0.7 mass% of C, 0.5 to 3 mass% of Si, 0.1 to 2 mass% of Mn, up to 3 mass% (exclusive of 0 mass%) of Cr, up to 0.1 mass% (exclusive of 0 mass%) of Al, up to 0.02 mass% (exclusive of 0 mass%) of P, up to 0.02 mass% (exclusive of 0 mass%) of S and up to 0.02 mass% (exclusive of 0 mass%) of N. The content of retained austenite in the inner surface layer of the steel pipe is 5 vol% or less. The average grain diameter of ferrite/pearlite phase in the inner surface layer of the pipe is 18[mu]m or less. The number density of carbide particles which have equivalent circle diameters of 500nm or more and which are present in the inner surface layer of the pipe is 1.8*10-2/[mu]m2 or less.