This paper describes an apparatus and a process for quasi-continuous flow of solids for extractions or reactions with compressed fluids at elevated pressure. The apparatus consists of a hollow cylinder built from steel as a pressure resistant jacket, in which a piston can be inserted. This piston consists of solid stamps at both ends. which are connected with intermediate elements, and thus form chambers with the jacket. These chambers can be filled with solids or pastes. The piston is moved through the jacket and the solid gets in contact with the compressed fluid and is extracted. After passing the jacket the chambers are discharged and recharged again, and the piston is moved through the jacket again. Thus a quasicontinuous or with an increasing number of chambers a nearly continuous flow of the solid can be achieved. It is shown that the optimal conditions for the quasi-continuous extraction are already defined by the initial rise and the maximum yield of extract mass as a function of time, which can be obtained from the simple batch extraction.