A method for manufacturing a terminal-equipped electric wire is a method in which an exposed core wire of the electric wire is ultrasonically welded to a core wire connection portion of a terminal having a core wire connection portion and a coating crimping portion. The manufacturing method for the terminal-equipped electric wire including: supporting the core wire connection portion on an anvil; bringing the coating crimping portion into contact with a vibration suppressing contact portion; arranging the exposed core wire on the core wire connection portion and arranging the coating of the electric wire in the coating crimping portion; and ultrasonically welding the exposed core wire to the core wire connection portion in a state where the core wire connection portion is supported on the anvil and the coating crimping portion is in contact with the vibration suppressing contact portion.