The amorphous Fe_73Si_16B_7Nb_3Cu_1(at%) alloy strip was pulverized using a jet mill and an attrition mill to get flake-shaped powder. The flake powder was mixed with dielectric BaTiO_3 powder and its dispersant to increase the permittivity. The powders covered with dielectric powders and its dispersant were mixed with a binder and a solvent and then tape-cast to form sheets. The absorbing properties of the sheets were measured to investigate the roles of the dielectric powder and its dispersant. The results showed that the addition of BaTiO_3 powders and its dispersant improved the absorbing properties of the sheets noticeably. The powder sheet mixed with 5 wt% of BaTiO_3 powder and 1 wt% of dispersant showed the best electromagnetic wave absorption rate because of the increase of the permittivity and the electrical resistance.