A connection module includes a FPC and bus bars connected to the FPC and connecting the electrode terminals of power storage elements that are adjacent to each other. The FPC includes a first wiring portion, a second bus bar mount portion, and a third bus bar mount portion to which the bus bars are connected. The FPC further includes a second expandable/contractable portion and a third expandable/contractable portion. The second expandable/contractable portion is continuous from the second bus bar mount portion and allowed to be expanded and contracted in a direction to be closer to and farther away from the first wiring portion and the third bus bar mount portion. The third expandable/contractable portion is continuous from the third bus bar mount portion and allowed to be expanded and contracted in a direction to be closer to and farther away from the second bus bar mount portion.