A conductor of an aluminum electric wire having a solder coating film thereon is placed on a conductor crimping part. The conductor crimping part includes a strongly crimped part where solder coating film of the conductor part is crimped with a strength to allow a break to occur due to application of a crimping force, and a weakly crimped part where solder coating film of the conductor part is crimped with a strength to prevent a break from occurring due to application of the crimping force. The conductor part and the conductor crimping part are electrically connected.