A hollow stabilizer includes a curved part having eight regions defined in a cross section. A first region includes a 90° first part when the center of the inside of the curve is taken to be at 0° and the center of the outside of the curve is taken to be at 180°. A third region includes a 0° third part. A fifth region includes a 270° fifth part. A seventh region includes a 180° seventh part. The radii of curvature of the respective outer surfaces of the third part and the seventh part are larger and the radii of curvature of the respective outer surfaces of the second part and the sixth part are smaller than the radii of curvature of the respective outer surfaces of the fourth part and the fifth part.