$(Ga_2O_3)_x(ZnO)_{100-x}$ (GZO) films were prepared at room temperature by using a facing target sputtering (FTS) system and their electrical resistivites was investigated as a function of the $Ga_2O_3$ content. The GZO film with an atomic ratio of $Ga_2O_3$ of x= 7 wt.%, shows the lowest resistivity of $7.5{ imes}10^{-4}{Omega}{cdot}cm$. The GZO films were also prepared at various substrate temperatures from room temperature to $300^{circ}C$, and their electrical resistivity was found to be improved as the substrate temperature was increased, A very low resistivity of $2.8{ imes}10^{-4}{Omega}{cdot}cm$ that is almost comparable with that of ITO film was obtained in the GZO films prepared at the substrate temperature of $300^{circ}C$ by using the FTS.