The subject matter of the invention is a process of dehydration of biological products using the pressurized drying method in which the product is treated with a gaseous medium the movement of which over the dried product is forced in a closed system under appropriate pressure, in the presence of a difference between the temperature of the medium circulating in the system and the temperature of the dried product until the product moisture content is reduced to the desired level, and in which the dehydration process is executed at a constant temperature of the atmosphere surrounding the material, preferably higher than its storage temperature but lower than the degradation temperature of its components.;In accordance with the essence of the invention, the process is carried out in a dehydration chamber where the dried product is placed on drying trays arranged on at least one rack with shelves fitted with heating surfaces, whereby at the beginning of the drying process the gaseous medium is nitrogen at a tempe
