Germanium is recognized as a critical and rare element, since it lacks primary resources and is extracted as by-product of zinc and copper refining. This element has high-tech applications in optics and electronics industries. Therefore, recycling of germanium from spent resources is an important task to create a sustainable approach for solving the concerns about unavailability of the element for future. In this study, extraction of germanium from semiconductor diodes, was investigated for the first time, using acetic acid as a comparatively green reagent. The characterizations results showed that sample contains 5092 ppm germanium. The X-ray diffraction analysis indicated that the main phases of germanium in sample are Ge and GeO₂. The effects of acetic acid concentration, stirring speed, and temperature were studied on germanium leaching kinetics. The obtained results showed that more than 70% of germanium was extracted from diode samples by using 2.5 M of acetic acid at 90 °C, after 240 min processing. The kinetic modeling indicated that germanium dissolution followed three phases. Diffusion control, and interfacial transfer and diffusion across the product layer were the limiting-rate step in germanium leaching in all phases. The leaching rate coefficients were very high for the first and third phases, while they were very low for the second phase. XRD interpretation and theoretical background discussed on solution chemistry are consistent with the results of leaching process. The SEM was employed to validate the results of kinetic modeling.