A new electroless plating process for preparing a copper layer with strong adhesion to glass substrates. This process incorporates a ZnO thin film on the glass substrate, instead of etching and sensitizing the substrate surface as in a conventional electroless plating process. The copper layer so obtained had a mirror-like finish while maintaining strong adhesion, even on a very smooth glass surface (Ra<0.01 μm). The bond strength measured by pull tests was more than 10 kg per 2 mm×2 mm square (kg/2 mm□), much greater than that obtained using conventional electroless plating (∼1 kg/2 mm□)and suitable for use in printed circuit boards. The ZnO thin film serves as a kind of «adhesive» between the metal layer and glass substrate.