Abstract: The invention relates to an extruder which has an extruder housing. The housing has at least two housing parts and is provided with a delivery channel in order to extrude a medium, at least one screw conveyor being located in said channel. The extruder housing is releasably retained on a frame by means of a first retaining device and a shaft section of the screw conveyor is releasably connected to a drive device. According to the invention the housing parts are fixed relative to one another by means of a second retaining device and the extruder housing is connected to the frame and secured against displacement in the longitudinal direction of the extruder housing by means of a third retaining device. When the first and third retaining device) are released, the housing parts can be removed as a unit from the frame.