PURPOSE: To improve the efficiency of electromagnetic wave absorption, by arranging and installing electromagnetic wave absorbing elements wherein electric resistance thin film is formed on the surface of a solid pole made of electric nonconductive material, on a grounded shielding wall having an uneven surface.

CONSTITUTION: An electromagnetic wave absorbing element is formed, by coating the whole surface of a square pole 3 made of electric nonconductive material with an electric resistance thin film 4. The sheet resistivity of the electric resistance film is gradually decreased in the manner in which the attenuating action of a waveguide is comparatively weak at an incidence side 2A, and strongest at a final end side 2D, when electromagnetic wave 5 enters a plane of incidence 6. The total length of an element 2 can be so selected that the attenuation becomes a desired value. A grounded shielding wall 7 is made of, e.g., a thin iron plate provided with an uneven surface 8 having an inclination angle of about 30∼60°. Incoming electromagnetic waves are completely cut off, and scattered and dispersed to be attenuated. A lot of the electromagnetic absorbing plates 1 wherein a lot of the elements 2 are joined, are arranged and installed on a necessary wall by conductive bonding. An electromagnetic dark room is formed, thereby.