We investigated the transmission coefficient, reflection coefficient, and absorbing property of metamaterials using a two-dimensional array of broadside-coupled split ring resonators (BC-SRRs) in free space measurement systems. The resonant frequency is dependent on the dielectric substrate thickness, and the BC-SRRs absorbed electromagnetic waves when a metal plate was placed on the back surface of the sample. Although the derived relative permittivity showed a negative imaginary part in some frequency regions, the correctness can be confirmed from the physical point of view by conversion to the characteristic impedance and the propagation coefficient. The unit cell size of the BC-SRR can be miniaturized to be near 1/14 compared to the free space wavelength.