PURPOSE: To prevent the squeeze-out of a plating metal by providing a means of preventing the squeeze-out of the partially plated metal outside of a mold resin on the side of part covered with the mold resin of an inner lead.

CONSTITUTION: A V-shaped groove 3 is provided on the side 1a of an inner lead 1. The V-shape grove 3 prevents the external squeeze-out of a plating liquid when partial plating is carried out even if the upper and the lower surfaces of the inner lead 1 are held by a mask and a plating metal 2 is not adhered to the outside from the V-shape groove. Accordingly, the plating metal 2 is not squeezed out toward the outside of a mold resin.