PURPOSE: To remove the resin projections of the base ends of leads by flattening the bottom face of a resin armor by pressurization from the lead tips while the resin is viscous during semi-hardening.

CONSTITUTION: After powder coating of thermosetting resin, the resin is uniformly pressurized in the direction of the base ends from the tips of leads while the resin is viscous during semi-hardening to flatten the bottom face of a resin armor. That is, the resin is molded while viscous during semihardening, therefore, the bottom face of the resin armor can be flattened by pressurization from the lead tips with appropriate jigs 20A and 20B. The resin is hardened by regular hardening without resin drop with its bottom face kept flat. Thereby electronic parts can be soldered to a substrate perpendicularly in a good soldering state without imperfect soldering.