PURPOSE: To provide a radio wave absorbing system which is easily arrayed on the surface of an object, which is complicated in configuration, but requires the absorption of an external wave, as well as a system which is adjustable in wave absorbing characteristics, in responsive to the frequency of the external wave.

CONSTITUTION: A circuit 2, being made up of material having the wave transmission characteristics, is arrayed on the surface of an object, wherein the circuit 2 circulates therein a powder mixed fluid 7 which is a mixture of fluid and wave absorbing powders. This arrangement renders a wave absorbing system less restricted both in design and structure as compared with an existing solid wave absorber, and applicable for the surface of an object which is complicated in configuration. Moreover, the wave absorbing characteristics of the system can be adjusted in response to the frequency of an incoming wave by means of a quantity adjusting apparatus 6 for powders, wherein the adjusting apparatus is capable of regulating the density of the wave absorbing powder, of the powder mixed fluid 7, circulating inside the circuit 2.