PURPOSE: To make it possible to maintain fairly strong bonding strength with the base of electronic parts even in the application exposed to great temperature change by so arranging that a metal piece which is plated with solder film in advance and a connecting piece may be spot-welded.

CONSTITUTION: Solder plating is applied to the first plate material consisting of copper or copper alloy and the second plate material consisting of metal material whose line expansion coefficient is between the first plate material and the base in electronic parts in a previous plating process 100, and a conductive piece for electronic parts is manufactured through a form pressing process 200, a spot-welding process 300 and a press formation process 400. Hereby, as compared with the case where solder plating is executed after the joining of the first plate material and the second plate material, the deformation in the solder plating process is small and a conductive piece for electronic parts which is extremely small in dimensions can be manufactured with high accuracy and there is neither exudation of solder plating liquid from the gap, etc., between the first and second plate material after spot welding nor pollution of water, etc., thus the quality of the solder plating is never impeded.