A battery includes a safety valve configured to cause a deformation due to an increase in internal pressure of the battery; a restraining part including a plurality of first protrusions provided along a first circumference to serve as a restrainer against a lead part when the safety valve and the lead part are shut off due to deformation of the safety valve; and an insulating holder including a plurality of second protrusions provided along a second circumference to insulate the safety valve and the restraining part, where a number of the first protrusions and the second protrusions arranged on a diagonal line including the first circumference and the second circumference is 3 or less.