A Ni—Cr alloy tube demonstrating an excellent corrosion resistance in a high temperature water environment can be provided, wherein the difference between uniform lattice strains of the surface layer thereof satisfies the following formulas (1) and (2). S≦0.002  (1) S=D500−D≦200  (2) wherein the meanings of the individual symbols in the above described formulas are as follows: S: The difference between uniform lattice strains (Å) of the surface layer D500: The {111} interplanar spacing (Å) at a depth of 500 nm from the material surface D≦200: The average value of the {111} interplanar spacings (Å) at the depth of 200 nm or less from the material surface.