  We study spin-dependent transport properties in magnetic tunneling junctions
(MTJs) with semiconductor barriers, Fe/CuInSe$_2$/Fe(001) and
Fe/CuGaSe$_2$/Fe(001). By analyzing their transmittances at zero bias voltage
on the basis of the first-principles calculations, we find that spin-dependent
coherent tunneling transport of $\Delta_1$ wave functions yields a relatively
high magnetoresistance (MR) ratio in both the MTJs. We carry out a detailed
analysis of the band-resolved transmittances in both the MTJs and find an
absence of the selective transmission of $\Delta_1$ wave functions in some
energy regions a few eV away from the Fermi level due to small band gaps in
CuInSe$_2$ and CuGaSe$_2$.
