A method and a device for admixture of powder in a liquid, whereby the method comprises that the liquid in a supply (14), influenced by underpressure in a crucible (12) to which the liquid is to be transferred, flows through a drain tube (6) out of the supply (14), the powder is dosed from a powder receptacle (1) and is driven by a gas, and the mixture of powder and gas is added to the liquid in the drain tube (6) and mixed therewith, whereupon the mixture flows into the crucible (12). The device comprises a supply (14) from which the liquid may flow and a receptacle (1) with powder, whereby a drain tube (6) connects the supply (14) with a receiving receptacle (12) which can be held at an inner underpressure. A device (4) for supply of a driving gas for the powder is connected to a mixing chamber (3) at an outlet from the powder receptacle (1), while the mixing chamber (3) is connected to the drain tube (6) for supply of powder to the liquid flowing in the drain tube.