PURPOSE: To make it possible to obtain an excellent thin absorbent material by sufficiently combining ferrite powder of a weight part in a fixed range with iron powder, which does not exceed the weight part of a constant value, corresponding to a frequency to be used.

CONSTITUTION: Together with ferrite powder, iron powder is kneaded at the same time with a hardenable binder; the dielectric constant can be increased by the dielectric effect of the iron powder while the thickness is made thin. In this case, the quantity of the ferrite powder to be mixed should be changed within the range from weight parts 5 to 90 and the quantity of the iron powder should be changed from weight parts 1 to 60 corresponding to a frequency to be used, so as to combine the ferrite powder with iron powder by using a sufficient quantity of the binder. Consequently, an excellent thin radio-wave absorbent material can be obtained.