The invention provides a raw steel sheet for obtaining a high-strength nonmagnetic austenitic stainless-steel material therefrom which has a high elastic-limit stress and excellent toughness. The raw steel sheet is an austenitic stainless-steel sheet that has a composition which contains, in terms of mass%, up to 0.12% C, 0.30-3.00% Si, 2.0-9.0% Mn, 7.0-15.0% Ni, 11.0-20.0% Cr, and up to 0.30% N and further contains at least one of up to 3.0% Mo, up to 1.0% V, up to 1.0% Nb, up to 1.0% Ti, and up to 0.010% B, with the remainder comprising Fe and unavoidable impurities, and which has an Ni equivalent of 19.0 or greater, wherein when the average crystal-grain diameter of the austenite is expressed by d (mu m), the value of d-1/2 is 0.40 or greater. The raw steel sheet has the property of having a magnetic permeability mu of 1.0100 or less after cold-worked so as to result in an equivalent strain of 0.50 or greater.