Hollow seamless pipe for high-strength spring

A hollow seamless pipe suitable for a high-strength spring, comprising a steel material comprising 0.2 mass % to 0.7 mass % of C, 0.5 mass % to 3 mass % of Si, 0.1 mass % to 2 mass % of Mn, more than 0 mass % and 0.1 mass % or less of Al, more than 0 mass % and 3 mass % or less of Cr, more than 0 mass % and 0.02 mass % or less of P, more than 0 mass % and 0.02 mass % or less of S, and more than 0 mass % and 0.02 mass % or less of N, wherein a depth of a whole decarburized layer in an inner surface layer part is 100 μm or less, a depth of a flaw which is present in an inner surface is 40 μm or less, a width of the flaw is 60 μm or less, and a number density of a carbide which has a circle equivalent diameter of 500 nm or more and is present the inner surface layer part is 1.8×10−2 particles/μm2 or less.