Provided is a method capable of reducing the amount of a coating part remaining between a conductor and a bonding object. A chip comes closer to an anvil so that the flat cable and the terminal are sandwiched between the chip and the anvil. The flat cable and the terminal are pressed so as to come close to each other. When the chip ultrasonically vibrates, vibrations of the chip propagate to the terminal, causing the terminal to ultrasonically vibrate. Then heat is generated in a plate part by friction between the chip and the plate part. The coating part being positioned between the conductor and the plate part melts from the generated heat and is removed. Thereby the conductor and the plate part come into contact with each other resulting in a solid-phase bonding together.