The extraction cell is filled with the solid sample to be examined and placed in a temperature-controllable oven. After adding the solvent, the cell is heated at constant pressure (adjustable between 0.3 and 20 MPa) up to a maximum temperature of 200°C and kept at constant conditions for a while so that equilibrium can be established. The extract is then transferred to a sample tube. A sample often goes through several extraction cycles. Finally, the extraction cell is rinsed with solvent, the rinsing valve is opened and the cell and all lines are rinsed with nitrogen and the apparatus is prepared for further extractions.