A wire harness for supplying electric power and transmitting communication signals to one or a plurality of electric components (3a-3i) mounted on a vehicle, the wire harness comprising: a plurality of control boxes (11a-11d) dispersedly arranged on the wire harness and configured to be able to control input and output of at least one of the electric power and the communication signals; a trunk harness (4a-4h) connecting one of the control boxes (11a-11d) to another of the control boxes (11a-11d); and a branch harness connecting the control boxes (11a-11d) to the electric components (3a-3i), the control boxes (11a-11d) being configured to be able to multiplex and demultiplex the communication signals, the trunk harness (4a-4h) having a common internal wire structure without relating to the control boxes (11a-11d) where the trunk harness is connected, at least one of the control boxes (11a-11d) being integrated with a functional component (12, 33) to be a component module, the functional component (12, 33) being configured to be able to input and output information relating to at least one of the electric components (3a-3i), the component module comprising a trunk connection reception hole to allow a connection of a trunk harness (4a-4h) connecting the component module with another control box (11a-11d) located on the wire harness and a branch connection reception hole to allow a connection of a branch harness connecting the component module with the electric components (3a-3i), characterized in that: the branch connection reception hole is different in shape from the trunk connection reception hole to enable distinguishing between the truck harness (4a-4h) and the branch harness to be connected, the trunk connection reception hole and the branch connection reception hole have different sizes corresponding to allowable current values of the trunk harness (4a-4h) and the branch harness to be connected thereto, and the trunk connection reception hole is larger than the branch connection reception hole. a plurality of control boxes (11a-11d) dispersedly arranged on the wire harness and configured to be able to control input and output of at least one of the electric power and the communication signals; a trunk harness (4a-4h) connecting one of the control boxes (11a-11d) to another of the control boxes (11a-11d); and a branch harness connecting the control boxes (11a-11d) to the electric components (3a-3i), the control boxes (11a-11d) being configured to be able to multiplex and demultiplex the communication signals, the trunk harness (4a-4h) having a common internal wire structure without relating to the control boxes (11a-11d) where the trunk harness is connected, at least one of the control boxes (11a-11d) being integrated with a functional component (12, 33) to be a component module, the functional component (12, 33) being configured to be able to input and output information relating to at least one of the electric components (3a-3i), the component module comprising a trunk connection reception hole to allow a connection of a trunk harness (4a-4h) connecting the component module with another control box (11a-11d) located on the wire harness and a branch connection reception hole to allow a connection of a branch harness connecting the component module with the electric components (3a-3i), characterized in that: the branch connection reception hole is different in shape from the trunk connection reception hole to enable distinguishing between the truck harness (4a-4h) and the branch harness to be connected, the trunk connection reception hole and the branch connection reception hole have different sizes corresponding to allowable current values of the trunk harness (4a-4h) and the branch harness to be connected thereto, and the trunk connection reception hole is larger than the branch connection reception hole. the branch connection reception hole is different in shape from the trunk connection reception hole to enable distinguishing between the truck harness (4a-4h) and the branch harness to be connected, the trunk connection reception hole and the branch connection reception hole have different sizes corresponding to allowable current values of the trunk harness (4a-4h) and the branch harness to be connected thereto, and the trunk connection reception hole is larger than the branch connection reception hole.