A device is provided with which it is possible to produce poly(methyl methacrylate) bone-cement paste, which is degassed to the greatest extent possible, while avoiding large-volume mixing containers and large cement volumes contained therein. The device includes a tubular hollow body (10) having a first opening (30) on the input side and a second opening (20) on the output side, at least one rotatably-mounted shaft (40) arranged in the axial direction in the tubular hollow body (10), thread turns (50) arranged axially along the outer side of the shaft (40), wherein the shaft (40) has at least one section with thread turns (50) whose pitch decreases in the direction of the second opening (20), at least one stirring blade (60) arranged on the shaft (40), and rigid mixing elements (70) arranged on the inner side of the tubular hollow body (10).