It is aimed to build a trunk line of an in-vehicle network having low connection resistance. The in-vehicle network is composed of a trunk line (1) and branch lines (2) branched from branch points (3) arranged at a plurality of intermediate positions of the trunk line (19 via connectors (CO) and to be connected to electronic control units (U). A bypass bypassed toward the connector (CO) from the trunk line (1) is formed at each branch point (3) of the branch line (1), and an exposed part of a core (7) is formed in this bypass and connected to a trunk line terminal (6). A branch line terminal (8) connected to an end of the branch line (2) and the trunk line terminal (6) are connected inside the connector (CO).