Abstract: In order to obtain starch and proteins from the flour of legumes, in particular peas, the legume flour which has been treated with an aqueous decomposing agent, is fed into a first section (I) of a process line with several solids-liquids separation stages (6, 9, 10) for the purpose of extracting the proteins. The solid phase suspended in water from the final solids-liquids separation stage (10) of the first section (I) is then fed continually into a second section (II) of the process line with at least one separation stage (11) for separating the fibers from the starch and at least one solids-liquids separation stage for separating the starch from the liquid phase. The aqueous decomposing agent is formed from an alkaline concentrate (B) and the liquid phase separated by the starch in the second section of the process line.