A microstructured separation device for separating parts of a liquid which comprises liquid components and at least one type of particle and/or at least one complex of interconnected particles of at least one type, with the following features: the device has an inlet for the liquid, a collection section, and a transport path from the inlet to the collection section; the transport path includes, situated one after the other in the direction of transport, a resuspension section, an incubation section, a first separation section for holding back at least some of the complexes and/or for slowing down the movement of at least some of the complexes and/or at least some of the particles, and a second separation section for holding back at least some of the complexes and/or at least some of the particles and/or for slowing down the movement of the particles; and the first separation section and second separation section have a microstructure with one or more microstructure elements.