Wire harness unit

A wire harness unit (10) according to one embodiment of the present disclosure is provided with: a plurality of conductive paths (11) that conduct electricity between in-vehicle devices; and a cooling unit that cools the plurality of conductive paths. The plurality of conductive paths have a first conductive path (20) and a second conductive path (30) arranged side by side with the first conductive path. The first conductive path has a hollow cylindrical first inner insulating layer (22) and a first cylindrical conductor (21) covering the outer peripheral surface thereof, and the second conductive path has a hollow cylindrical second inner insulating layer (32) and a second cylindrical conductor (31) covering the outer peripheral surface thereof. The cooling unit has a cooling pipe (40) that allows a cooling medium to flow therethrough, is separate from the first inner insulating layer and the second inner insulating layer, and has a first section (41) that penetrates the first inner insulating layer, a secon