Battery pack, busbar holder used for battery pack, and method for manufacturing battery pack

A battery pack includes a plurality of unit cells, a plurality of busbars, a support member and a busbar holder. The unit cells have electrode tabs. The busbars have connection portions joined to the electrode tabs. The support member supports the electrode tabs. The busbar holder retains the busbars. The busbar holder has pressing parts that press the connection portions of the busbars toward the electrode tabs supported by the support member, and deforming parts that urge the pressing parts with a repulsive force in a direction in which the pressing parts are caused to move toward the electrode tabs. The deforming parts have leg parts that extend so as to project in a direction away from the busbars.