In a structure in which a crimping terminal (10) in which an electric wire connection part (12) is formed in substantially a U shape in cross-section view by having base plate parts (21, 23) and pairs of electric wire crimping pieces (22, 24) is used and a metallic tubular cap (30) is attached to a conductor (Wa) exposed by removing a portion of an insulating sheath (Wb) of the distal end of an electric wire W and the electric wire crimping pieces (22, 24) are crimped while crushing the conductor (Wa) of the distal end of the electric wire W together with the cap (30) thereon, a front end (31) of the cap (30) is crushed and thereby the front end of the cap (30) is sealed with its crush part (35).