Abstract: The Taguchi method was used to obtain the optimum electrodeposition parameters for the synthesis of the CuInSe₂ thin film for solar cells. The parameters consist of annealing temperature, current density, CuCl₂ concentration, FeCl₃ concentration, H₂SeO₃ concentration, TEA amount, pH value, and deposition time. The experiments were carried out according to an L₁₈(2¹3⁷) table An X-ray diffractometer (XRD) and a scanning electron microscope (SEM) were respectively used to analyze the phases and observe the microstructure and the grain size of the CuInSe₂ film before and after annealing treatment. The results showed that the CuInSe₂ phase was deposited with a preferred plane (112) parallel to the substrate surface. The optimum parameters are as follows: current density, 7 mA/cm 2 ; CuCl₂ concentration, 10 mM; FeCl₃ concentration, 50 mM; H₂SeO₃ concentration, 15 mM; TEA amount, 0 mL; pH value, 1.65; deposition time, 10 min; and annealing temperature, 500℃.