The electromagnetic wave (EM) absorption properties of various particle size have been investigated in a sheet-type absorber using the alloy powder. With decreasing the average particle size, the complex permeability () and permittivity () increased and the matching frequency is shifted toward lower frequency. The fabricated EM wave absorbers showed permeability , permittivity for a mesh sample, and the calculated power absorption was as high as 80% in the frequency range over 2 GHz.