A plant for an extraction process with a liquid passing through a matrix consisting of organic and/or inorganic type residues, the plant comprising: - At least one high pressure section configured to bring the liquid into a subcritical condition, said high pressure section comprising: - a) At least one tank (S301, S401) forming a containment volume for the containment of one or more baskets each adapted to contain an organic and/or inorganic matrix; - b) One or more of said baskets; - c) A delivery duct entering the containment volume of the tank to lead the liquid into said tank and an outlet duct to lead the liquid out of said tank; - And wherein at least the part of the delivery duct arranged in the containment volume of said tank (S301, S401) and said one or more baskets have a distribution of holes in such a way that at least a part of the liquid entering the containment volume spreads radially into the containment volume, hitting and passing through said baskets radially through the distribution of holes in said baskets; - Characterized in that: - The delivery duct extends into the containment volume and is provided with a plurality of through holes along its length, each basket forming an annular space for containing the matrix delimited by a first wall and a second wall that surrounds the first wall, said first and second walls being equipped with a plurality of through holes (11", 14) and with the first wall which is in the form of a longitudinally hollow tube so as to form an axial channel of such size as to be able to slidingly house the delivery duct along it, so that one or more baskets can be stacked inside the containment volume with the delivery duct which slides into and crosses said channel of each basket. - At least one high pressure section configured to bring the liquid into a subcritical condition, said high pressure section comprising: - a) At least one tank (S301, S401) forming a containment volume for the containment of one or more baskets each adapted to contain an organic and/or inorganic matrix; - b) One or more of said baskets; - c) A delivery duct entering the containment volume of the tank to lead the liquid into said tank and an outlet duct to lead the liquid out of said tank; - And wherein at least the part of the delivery duct arranged in the containment volume of said tank (S301, S401) and said one or more baskets have a distribution of holes in such a way that at least a part of the liquid entering the containment volume spreads radially into the containment volume, hitting and passing through said baskets radially through the distribution of holes in said baskets; - Characterized in that: - The delivery duct extends into the containment volume and is provided with a plurality of through holes along its length, each basket forming an annular space for containing the matrix delimited by a first wall and a second wall that surrounds the first wall, said first and second walls being equipped with a plurality of through holes (11", 14) and with the first wall which is in the form of a longitudinally hollow tube so as to form an axial channel of such size as to be able to slidingly house the delivery duct along it, so that one or more baskets can be stacked inside the containment volume with the delivery duct which slides into and crosses said channel of each basket.