Austenitic stainless steel and spring

The present invention is an austenitic stainless steel which contains, on a mass basis, from 0.01% to 0.2% of C, 2% or less of Si, 3% or less of Mn, 0.035% or less of P, 0.03% or less of S, from 6% to 14% of Ni, from 20% to 26% of Cr, 3% or less of Mo, from 0.01% to 3% of Cu, 1% or less of Ti, 0.2% or less of Al, 0.1% or less of Ca, from 0.1% to 0.25% of N and 0.008% or less of O, with the balance being made up of Fe and impurities, wherein the E value obtained by formula (1) is -17.0 or more and the F value obtained by formula (2) is 0 or more. (1): E = -0.33 × SFE + 0.25 × R In formula (1), SFE = 25.7 + 2Ni + 410C - 0.9Cr - 77N - 13Si - 1.2 Mn (wherein the atomic symbols represent the contents (mass%) of the respective elements); and R represents the average crystal grain size (μm). (2): F = 1003O - 211Al - 158Ca - 79Ti In formula (2), the atomic symbols represent the contents (mass%) of the respective elements.