A wave absorber of the present invention includes a sequentially laminated structure including an conductor layer (11) made of a conductive material; a first dielectric layer (polycarbonate substrate (12) and bismaleimide-triazine substrate (13)) made of one layer or a multilayer of a dielectric material; and a patterned layer (14) including a plurality of a pattern made of the conductive material, wherein the conductor layer, the first dielectric layer, and the patterned layer are laminated sequentially, and each pattern in the patterned layer (14) is different from other adjacent patterns with respect to at least one of size and shape. Therefore, the wave absorber has sufficient reflection-attenuating capability to prevent communication failure caused by a reflection of a radio wave and so on, can be thin-sized and reduced in weight, and has a wide-band attenuation property.