The present invention relates to a device at a bone cement mixer, wherein thebonecement mixer (1) comprises at least one mixing space (5) for mixing powder andliquidcomponents (2, 4), preferably a polymer and a monomer respectively, to makebonecement, the powder component (2) is placed in the mixing space (5) and theliquidcomponent (4) in a liquid container (3), and the liquid component (4) issucked out fromthe liquid container (3) to the mixing space (5) and the powder component (2)placedtherein by means of vacuum generated in said mixing space. According to theinvention, the liquid container (3) is a tube (15) or bag of such metalmaterial whichprevents the liquid component (4) from escaping from it, has the tube (15) orbag aconnecting element (16) for connecting it to the bone cement mixer (1), is thetube (15)or bag closed and adapted to being opened when it is connected to acorrespondingconnecting element (17) on the bone cement mixer (1), so that the liquidcomponent (4)is sucked out from the tube or bag into the mixing space (5) by means of saidvacuumtherein, and is the tube (15) or bag designed and the metal material of thetube or baghas a thickness such that the volume of its liquid containing space (18) isbrought todecrease when said vacuum in the mixing space (5) is brought to prevail alsothereinwhen the liquid component is sucked out therefrom.
