Relevance. When mining large iron ore deposits of the Kursk Magnetic Anomaly, one of the main problems is environmental safety, in particular, the maximum preservation of fertile soil. The underground mining method reduces the technogenic load on the natural environment and allows most of the mining waste to be placed in the mined-out space. However, main source of negative environmental impact is the processing production, which occupies large areas and is characterized by intense harmful emissions. Processing facilities placed underground significantly reduce this impact. Research objective is to assess the advisability of building an underground processing facility at the Voronets iron ore deposit. Methods of research. The work uses a comprehensive research method, including rational ore processing scheme justification, underground processing facility design, and a technical and economic comparison. Results. A scheme of ore processing with the production of a high-quality concentrate is presented, and a chain of mechanisms and apparatus for all stages of ore processing is selected, including its crushing, grinding, magnetic separation and dehydration of the resulting products. Based on the parameters of the selected equipment, its underground layout is shown, the volume the processing facility chambers is calculated. It is shown that the entire volume of tailings is located in the chamber goafs of the underground mine and are not lifted to the surface. Conclusions. An approximate assessment of the effectiveness of the processing facility underground location has been made. It has been shown that the cost of building that facility is comparable to the cost of building a similar processing facility on surface. Placing the processing in underground makes it possible to significantly reduce the area of land allotment of the enterprise, to lift only concentrate on the surface, and to eliminate the negative environmental impact of processing production.