A wire harness includes a plurality of wires, and a connector including a housing for holding end portions of the plurality of wires. The housing includes an airtight block that includes a resin, an insertion hole formed thereon for inserting the plurality of wires, a flow channel in communication with the insertion hole to flow a molten resin therethrough for resin-sealing a gap between the insertion hole and the plurality of wires, and a melting section to be the molten resin being integrally formed with the flow channel. The gap between the insertion hole and the plurality of wires is resin-sealed such that an ultrasonic vibrator relatively moving with respect to the airtight block is brought into contact with the melting section, and the molten resin melted from the melting section by heat generated by vibration of the ultrasonic vibrator is poured into the gap.