A forming apparatus for forming a wire joint portion including a connection portion and an insulative tube covering the connection portion is provided. The forming apparatus includes: a production information acquiring unit which acquires production information; a connection portion forming unit which fixes a plurality of wires selected on the basis of the production information, and then electrically connects conductor portions of the wires together to form the connection portion; a first fusing unit which fuses one open end portion of the insulative tube to close the one open end portion; an inserting unit which moves the wires so as to insert the connection portion into the insulative tube through the other open end portion of the insulative tube; a second fusing unit which fuses the other open end portion of the insulative tube and insulative sheaths of the wires together so as to form the wire joint portion.