A rail vehicle body is made of stainless steel, wherein: the length members of the chassis and the roof battens are made of stainless steel, are constituted by section members that are continuous along the entire length of the body, and are visible; and the covering of the side faces comprises sheets of stainless steel that are smooth and thin relative to the thickness of said section members, the sheets being fixed by continuous leak-proof welding to the edges of the length members and to the roof battens so that the area of said metal sheets is as small as possible. The elements of the strength-providing structure are assembled together by weld fillets, and likewise the metal sheets are assembled to said strength-providing structure by weld fillets.