Abstract: In order to study the absorption characteristics of 10 GHz electromagnetic (EM) waves by femtosecond filaments array, the interaction model of electromagnetic wave and femtosecond filaments array is established, and the absorption coefficients with electron temperature, electron density, filament diameter, and EM polarization are calculated by the finite element method (FEM). The results indicate that the plasma filaments array becomes transparent for EM wave when the polarization of the EM waves is perpendicular to the filaments axis. The absorption coefficient increases first and then decreases with the increasing of the filaments electron density or electron temperature, when skin depth of EM wave is equal to the diameter of the filament, the absorption coefficient reaches the maximum. For the S-polarized EM wave, the absorption coefficient increases with incident angle when the diameter of the filament is 50 μm. There is an absorption peak at large angle when the filament diameter is between 100 μm to 200 μm, and the incident angle responding to the peak absorption is decreasing with the diameter of the filaments. For the P-polarized EM wave, the absorption coefficient is decreasing with the incidence angle of the EM wave.