Abstract: Method and device for the selective extraction of compounds, particularly biochemical compounds having a high added value, from a complex solution. The method makes use of a monoenzyme reactive membrane system (3, 4, 5, 6) in a liquid medium, at the interfaces of which an electrochemical potential gradient of one of the reagents creates asymmetrical conditions which force the reversible reaction catalyzed by the reactive membrane system to operate in opposite directions on either side of said system, the passage of the compound to be extracted from one side to the other being favored by the presence on both faces of said system of barriers (5) which confine a compound other than the compound to be extracted. Device for implementing such method. Application to the extraction of compounds which are interesting from a biochemical point of view by concentration and accumulation on one side of the membrane system.