A battery pack includes: a plurality of battery cells (1); a cell support that holds the plurality of battery cells; a connection part (6) that connects to the plurality of battery cells; and a circuit substrate (8) that is used to mount circuits for the plurality of battery cells. The cell support (2) is integrally formed with battery cell storage units (3) that store the plurality of battery cells, a base unit (4) that supports the battery cell storage units, and impact relaxation ribs (21), and each of the impact relaxation ribs is formed between an outer circumference of the base unit and an exterior surface of each of the battery cell storage units, and is configured in a shape capable of being transformed in a direction to which impact is applied.