In the present invention, a battery pack is provided with a sealed case and battery cells that are accommodated in the sealed case. The sealed case includes a case main body having an opening, and a lid member that is fixed to the case main body by means of a plurality of bolts and closes the opening. If the distance between adjacent bolts of the plurality of bolts is compared, the distance between a specific pair of adjacent bolts is longer than any distance between the remaining pairs of adjacent bolts.