Low-emissivity glass has high transmission in the visible region and high reflectivity in the infrared region. Gallium and aluminum codoped zinc oxide (GAZO) processed by hydrogen (H2) plasma treatment holds promise for fabricating good low-emissivity glass. The applied processing time is one of the key factors in plasma treatment. The GAZO films were prepared by in-line sputtering at room temperature, and the effect of using different plasma processing times on the structural, electrical and optical properties of the films were surveyed. Experimental results indicate that H2 plasma treatment of GAZO film samples indeed influenced the structure, optical and electrical properties. An appropriate processing time can improve the electrical properties and reduce the emissivity of GAZO films. The optimum processing time is 5 min for plasma treatment of GAZO films. The electrical resistivity and emissivity of plasma-annealed films for 5 min decrease by 59% and 55% compared to those of as-deposited GAZO films. Values of 5.3 × 10−4 Ω-cm in electrical resistivity, 0.13 in emissivity and 94% in average optical transmittance in the visible wavelength region could be obtained for GAZO films after H2 treatment of 5 min in this work for low-emissivity glass applications.