PURPOSE: To restrain the pinhole generation during the exterior packaging process by a method wherein the second low viscosity exterior resin packaging process is set up between the first and second high viscosity exterior resin packaging processes.

CONSTITUTION: An element main body 1 and a part of outer leads 2, 3 are dipped into a low viscosity exterior resin so that the element main body 1 and the outer leads 2, 3 may be coated with the specific amount of the first low viscosity exterior resin 5a to be dried up for packing the exterior. Likewise, the first high viscosity exterior resin 6a, furthermore the second low viscosity exterior resin 5b and the second high viscosity exterior resin 6b are used for packing the exterior. Accordingly, a pinhole 8 to be made during the exterior packaging process of the first high viscosity exterior resin 5a is successively impregnated with the second low viscosity exterior resin 5b sufficiently. Through these procedures, the pinhole to be made in the second high viscosity exterior resin 6b as the final exterior resin can be avoided.