Abstract: An apparatus capable of solder-plating only on lead-regions of a lead-frame carrying a multiplicity of electronic parts or components. It comprises a block made of a heat-resistant and solder-wettable metal immersed in a bath of molten solder. The block is provided with a horizontal path for the lead-frame at a plane sufficiently above a level of said molten solder, and a plurality of vertical conduits, extending from the bottom of the block, open at the horizontal path. The conduits are capable of replenishing the molten solder on a plateau provided on a lower inside face of the path by capillary action. The lead-regions of lead-frame which travels through the path contacts with the molten solder on the plateau.