A sheath (4) of an aluminum electric wire (1) is peeled, a distal end of an exposed conductor part (2) is tightened and connected after being placed in a conductor crimping part (13) of a crimped terminal (10) while being recessed to be further inside than the distal end of the conductor crimping part (13), and the distal end section of the conductor crimping part (13) of the crimped terminal (10) which forms an empty space where there is not the conductor part is welded and sealed.