The invention relates to a mixing device for mixing PMMA bone cement from a monomer liquid and a cement powder, the mixing device comprising at least one cartridge having an evacuable interior for mixing of the bone cement, a mixing device for mixing the content in the interior of the at least one cartridge, which is arranged movably in the interior, a receptacle for receiving a separate container containing the monomer liquid or comprising an integrated container containing the monomer liquid, an opening device, which is arranged in the region of the receptacle in a manner movable relative to the receptacle so that, by moving the opening device, a separate container arranged in the receptacle is openable by means of the opening device, or the opening device is arranged in the region of the integrated container in a manner movable relative to the integrated container so that, by moving the opening device, the integrated container is openable by means of the opening device, a pressure pump, in which a movable plunger for conveying a liquid is arranged and delimits a pump chamber of the pressure pump and a connection line, which connects the interior of the at least one cartridge to the pump chamber of the pressure pump, wherein the mixing device comprises an operating element that is operatable from outside, wherein the plunger in the pressure pump is movable manually by means of the operating element, and wherein the opening device is to be moved relative to the receptacle or relative to the integrated container by means of the same operating element, and the mixing device in the interior of the cartridge is movable by means of the same operating element in order to mix the content in the interior of the cartridge.
