To provide a composite type hollow radiowave absorber configuring a radiowave absorption wall capable of obtaining a return loss of -20 dB or more over a wide frequency band of approximately 30 MHz to 3 GHz, as well as the radiowave absorption wall and an anechoic chamber using the same.

A dielectric loss body 4 with an imaginary part of a complex dielectric constant ranging from 0.1 to 2.0 is provided in a hollow part of the composite type hollow radiowave absorber 1 including a hollow radiowave absorber made by forming a conductive thin plate 2 into a wedge shape or a pyramid shape having the hollow part and a ferrite tile 3, the dielectric loss body 4 includes an upper loss body 41 to be arranged at a tip of the hollow part and a lower loss body 42 to be arranged at a distance l from the ferrite tile 3. The upper loss body 41 has a thickness (d) no smaller than a twelfth of a wavelength λ, and the distance l is no shorter than one-sixth of the wavelength λ at a higher frequency among frequencies where the return loss of a radiowave across a resonance point of the ferrite tile 3 is -20 dB. The radiowave absorption wall and the anechoic chamber using the composite type hollow radiowave absorber are also obtained.