To manufacture a wire harness efficiently by suppressing tangling or snarl of a long electric wire with terminals.

The manufacturing method of a wire harness is provided with: a process in which a plurality of general electric wires with terminals shorter than a reference length are temporarily bound and a temporary bound harness is manufactured; a process of transferring the temporary bound harness; a process in which the temporary bound harness is wired on an assembly work bench 18; a process in which a plurality of long electric wires with terminals 14 longer than the reference length are transferred in a single wire configuration; and a process in which the plurality of long electric wires with terminals 14 are respectively supplied and wired on the assembly work bench 18 in a single wire configuration.