There is provided an austenitic stainless steel tube containing, by mass percent, 14 to 28% of Cr and 6 to 30% of Ni, wherein the steel tube has a metal micro-structure, in which an average dislocation density, which is determined by XRD measurement using a Co tube, is 3.0×1014/m2 or higher, on the inner surface side of the steel tube. The crystal grain size of the steel tube is preferably 50 μm or smaller. The steel tube of the present invention is suitable as a steel tube used in power-generating plants.