The purpose of the invention is to expand the clutch space where a first rotation axis member and a hub member that are connected to each other are disposed when structural elements are layout-placed around the clutch in a previously established axial direction space. The drive force transmission device is provided with a dry multi-plate clutch (7). The clutch drum (6) extends from a cylindrical part (6a) radially inward, is connected to a clutch drum shaft (4), and has a partition wall (6b) that partitions the space inside the drum into a bearing space (Sb) and a clutch space (Sc). A regulating part (81a) that regulates movement of the outer race (12b) of a first bearing (12) in the axial direction is provided at the end of the unit housing (81) on the partition wall (6b) side. The partition wall (6b) is disposed at a position on the inner circumference side of the regulating part (81a) offset towards the bearing space (Sb) side so as to overlap the regulating part (81a) in the radial direction.
