Abstract: The present invention relates to an electromagnetic wave absorbers in broad bands, which can be efficiently produced by a simple method, thereby reducing production costs, and for which working efficiency can be improved due to a reduction in weight. The absorber is capable of efficiently absorbing electromagnetic waves in broad bands. The electromagnetic wave absorber in broad bands is constructed by attaching sintered ferrite magnetic bodies, in which lattice bar portions are disposed at appointed intervals, to a metallic reflection plate. The lattice bar portions of the sintered ferrite magnetic bodies are such that sintered ferrite plates of an appointed thickness are formed curved at a base width and a height where openings are provided at the respective bases of the lattice bar portions, so that the interval between openings are gradually made narrow from the base to the upper end and the top parts are caused to converge to a width almost coincident with the thickness of said sintered ferrite plate.