PURPOSE: To prevent the oxidation of solder and the formation of solder bridges and solder flashes by providing escape holes for efflux of molten liquid in compartment to the guiding plates of the compartment with a top opening edge and a lower receiving port of a titled jet type device.

CONSTITUTION: Solder charged into a vessel 1 is heated and melted by a heater 5. When a propeller 7 is rotated by a motor 6, molten solder liquid passes through a receiving port 3 and flows into a compartment 4, from which it passes through a flow aligning plate 8 and flows out into the vessel 1 through escape holes 9, thereby circulating in the vessel. At this time, the flow rate of the molten liquid is controlled to prevent the liquid from flowing out from an opening edge 2 or to overflow therefrom to the extent of not allowing the flux carried in from the materials to be plated from diffusing, thereby maintaining a liquid level L2 of fixed height from the liquid level L1 in the vessel. If in this state electronic parts etc. of intricate shapes are solder plated, the escape of flux does not occur because the liquid level L2is in a state close to static. Since the efflux fall from the holes 9 is small, the formation or oxide produced on the solder surface may be reduced.