A nonaqueous electrolyte battery includes an outer case having one open end portion, a battery element held in the outer case, and a battery lid which is disposed on the one open end portion and which is provided with a protrusion portion protruded toward the outside of the battery, at least two opening portions disposed in the protrusion portion, and release portions disposed adjoining the respective opening portions so as to deform in accordance with an increase in internal pressure of the battery.