The electromagnetic (EM) wave absorption properties with a variation of crystallization annealing temperature have been investigated in a sheet-type absorber using the $Fe_{73}Si_{16}B_7Nb_3Cu_1$ alloy powder. With increasing the annealing temperature the complex permeability (${mu}_r$), permittivity (${varepsilon}_r$) and power absorption changed. The EM wave absorber shows the maximum permeability and permittivity after the annealing at $610^{circ}C$ for 1 hour, and its calculated power absorption is above 80% of input power in the frequency range over 1.5 GHz.