A wiring unit includes a wiring harness (WH), a holding plate (2) for holding the wiring harness (WH), pairs of through holes (21A, 21B) formed through the holding plate (2), and tie bands (20) inserted through the pairs of through holes (21A, 21B) to fix the wiring harness (WH) to the holding plate (2). Each tie band (20) includes a band portion (23) having longitudinally spaced locking teeth (24) on one surface and to be inserted through the pair of through holes (21A, 21B), and a lock (25) provided on one end of the band portion (23) and including an insertion opening (26), through which a free end of the band portion (23) is inserted. A locking claw (27) in the insertion opening (26) retains the band portion (23) by selectively locking to a locking tooth (24). The paired through holes (21A, 21B) have mutually different shapes.