The electrochemical synthesis of conductive polymers (CPs) or semiconductors (SCs) is influenced by several parameters, such as the choice of monomers, solvents, support electrolytes, and the nature of dopants, which induce electrical conductivity in conjugated organic polymers. This work describes the electropolymerization of 3-amino-1,2,4-triazole-5-thiol (ATT) on a 60Cu-40Zn brass alloy. The synthesis of polymer film by electrochemical method was carried out by cyclic voltammetry and chronoamperometry in a medium of KOH 0.1 M dissolved in pure methanol CH3OH. The voltammograms obtained show that the ATT oxidizes anodically at a potential of 1.15 V. The effect of the sweep speed shows that the increase in the sweep speed is accompanied by the increase in the intensity of the first oxidation peak, indicating the acceleration of the process studied, and also indicating that the oxidation reaction of the monomers is essentially irreversible and controlled by a diffusion process. The polymer film analysis by electrochemical impedance spectroscopy shows a capacitive then diffusional behavior—this is a typical effect of conductive polymers. Analysis by EDX justifies the formation of a polymer film on the metal surface. This work was completed by theoretical calculation, which showed that the oxidation of the ATT considerably reduces the energy value of Gap Egap, reaching a value of 2.07 eV—this shows that the polymer film is a semiconductive material.