In a method for manufacturing a blazed grating from a prefabricated initial blazed grating, a blazed grating the substrate of a first material of which has a surface, which has an initial surface profile having an initial blaze angle, is provided. An auxiliary layer of a second material is applied onto the surface of the substrate, wherein the second material is different from the first material. The auxiliary layer is removed at least partially by means of etching, wherein the etching is carried out at least until the etching simultaneously acts on the auxiliary layer and on the initial surface profile of the substrate. A ratio between an etching rate for the auxiliary layer and an etching rate for the substrate is adjusted such that the initial blaze angle is reduced to a final blaze angle. Further, a blazed grating manufactured in that way and an optical device having such a blazed grating, are described.