The paper describes an installation for the degradative depolymerization of polyolefin materials obtained from wastes, hereinafter also referred to as depolymerization for simplicity. The plant, on an industrial scale, is one of the few operating in Poland. However, it is one of the most modern plants in this industry. Design solutions, construction of particular technological lines, compliance with national and EU regulations and the high level of process safety were described in this paper as well as compared to other plants of this type in Poland. Different solutions were presented in drawings and photos of the plant and in fragmentary technological diagrams. The types of waste and the methods of their processing by the plant were also characterized in accordance with the applicable regulations. The waste throughput is from 2000 to 4000 kg/h, while the efficiency of the depolymerization installation itself is 1500 kg/h. The industrial-scale depolymerization process is carried out in one or two stages: by homogenization (extraction) at a temperature up to 200 °C and depolymerization at temperatures up to 400 °C. The obtained products (energy goods) are sold for further processing. The processes, devices and methods are characterized by novel, innovative solutions, covered by a number of patents, which are also described below. The advantage of the presented technology is the substantial simplification of the process and thereby a considerable reduction in investment costs. Among others, the processes of distillation and rectification (low- and negative-pressure) were abandoned.