A wire harness includes a trunk line which serves as a transmission line of power from a vehicle battery; and a plurality of power source control boxes which are provided on the trunk line, arranged one by one in each of a plurality of partitions into which a vehicle is partitioned, and distribute the power received through the trunk line to a power-demanding device that demands for supply of power. In at least one partition of the plurality of partitions, the power source control box of the corresponding partition is connected with entire first device arranged in the same partition to supply power among the first device and a second device, and includes a connection unit of a branch wire which is connected to a sub-power source control box that supplies power to the second device.