Abstract: A battery pack includes: a plurality of batteries; a housing for containing the batteries; and at least one partition plate for separating the batteries from one another. The at least one partition plate includes a metal mesh and a heat insulating layer disposed on each side of the metal mesh. The heat insulating layer includes a foam material capable of foaming at a temperature of 110° C. or more and 200° C. or less, so that the thickness of the heat insulating layer increases when the foam material foams. Even when one of the batteries contained in the battery pack generates abnormal heat, the conduction of the heat to other batteries can be effectively suppressed.