A wiring harness for connecting electrically between in-vehicle units includes a pitch ribbon cable having a plurality of bridge portions and a connector having a boss and a press-contact portion. Each bridge portion includes first, second and third notches. The third notch is engaged to another boss of the in-vehicle unit in case of assembling the pitch ribbon cable to the in-vehicle unit so that layout of the wiring harness becomes definite. The second notch is engaged to the boss of the connector in case of attaching the pitch ribbon cable to the connector. The first notch is engaged to the press-contact portion of the connector with using the second notch as a positioning reference so that positioning of the pitch ribbon cable becomes definite.