The present invention relates to a device at a bone cement mixer, wherein the bone cement mixer (1) comprises at least one mixing space (5) for mixing powder and liquid components (2, 4), preferably a polymer and a monomer respectively, to make bone cement, the powder component (2) is placed in the mixing space (5) and the liquid component (4) in a liquid container (3), and the liquid component (4) can be transferred from the liquid container (3) to the mixing space (5) and the powder component (2) placed therein. In order to effect quicker controllable and better distribution of the liquid component in the powder component and hence quicker controllable and better mutual mixing of them, the liquid container (3) is an aerosol container (15) and contains, in addition to the liquid component (4), a propellant gas for pushing the liquid component (4) out from the aerosol container (15) into the mixing space (5), the aerosol container (15) has a connecting element (16) for connecting it to the bone cement mixer (1), and the aerosol container (15) is closed and is adapted to being opened when it is connected to a corresponding connecting element (17) on the bone cement mixer (1), so that the liquid component (4) is pushed out from the aerosol container (15) into the mixing space (5) by said propellant gas.
