One aspect relates to a device for mixing a polymethyl methacrylate bone cement formed of two starting components and for storing the starting components of the bone cement. The device has a tubular cartridge with a cylindrical interior. A powder is contained in a front of the cartridge and a container containing a monomer liquid is arranged in a rear of the cartridge. A discharge piston is arranged between the container and the powder, and a conveying piston is on the side of the container opposite the discharge piston. The discharge piston and the conveying piston are arranged in the interior of the cartridge movably in the longitudinal direction. A conduit is provided that connects the front part and the rear part of the interior of the cartridge to one another in a manner permeable for the monomer liquid and for gases and which is impermeable for the powder.