PURPOSE: To easily form a rugged pattern on an electromagnetic wave absorber without spoiling an elecrtomagnetic wave loss material and necessitaing rigid dies and large-scaled facilities by mixing a soft material mixed with the electromagnetic wave loss material with a hardening material, putting it into the dies having a rugged pattern and hardening it.

CONSTITUTION: For example, a soft material 1 made of urethane foam is combined with an electromagnetic wave loss material. The electromagnetic wave loss material, may be a water-soluble conductive paint that contains carbon powder for making use of its dielectric loss. Then, a thermosetting resin as a hardening material such as an epoxy resin, etc., is mixed to the material 1 mixed with the electromagnetic wave loss material, and it is put into dies 2, hardened and taken out from the dies 2. As a result, an electromagnetic wave absorber 3 having a rugged pattern on its surface is obtained. Therefore, the absorber 3 can be molded by using simple dies 2.