A secondary battery comprising: a battery assembly configured by alternately stacking positive electrodes and negative electrodes (1, 6) via separators, wherein: the positive electrode and the negative electrode respectively include collectors (3, 8) and active materials (2, 7) applied on the collectors (3, 8); a coated portion in which the active material (2, 7) is coated and an uncoated portion in which the active material (2, 7) is not coated are provided on each surface of the collector (3, 8); in one or both of the positive electrode and the negative electrode, a boundary portion between the coated portion and the uncoated portion on a front surface of the collector (3, 8) is positioned planarly away from a boundary portion between the coated portion and the uncoated portion on a rear surface of the collector (3, 8), the secondary battery further comprising an insulating member which covers the boundary portion (4a, 4b) between the coated portion and the uncoated portion, and wherein when seen planarly, a distance between an end of the coated portion side of the insulating member located on the front or rear surface of the collector (3, 8), and the boundary portion (4a, 4b) between the coated portion and the uncoated portion on the other front or rear surface of the collector (3, 8), is larger by five times or more than an average thickness of the insulating member. a battery assembly configured by alternately stacking positive electrodes and negative electrodes (1, 6) via separators, wherein: the positive electrode and the negative electrode respectively include collectors (3, 8) and active materials (2, 7) applied on the collectors (3, 8); a coated portion in which the active material (2, 7) is coated and an uncoated portion in which the active material (2, 7) is not coated are provided on each surface of the collector (3, 8); in one or both of the positive electrode and the negative electrode, a boundary portion between the coated portion and the uncoated portion on a front surface of the collector (3, 8) is positioned planarly away from a boundary portion between the coated portion and the uncoated portion on a rear surface of the collector (3, 8), the secondary battery further comprising an insulating member which covers the boundary portion (4a, 4b) between the coated portion and the uncoated portion, and wherein when seen planarly, a distance between an end of the coated portion side of the insulating member located on the front or rear surface of the collector (3, 8), and the boundary portion (4a, 4b) between the coated portion and the uncoated portion on the other front or rear surface of the collector (3, 8), is larger by five times or more than an average thickness of the insulating member. the positive electrode and the negative electrode respectively include collectors (3, 8) and active materials (2, 7) applied on the collectors (3, 8); a coated portion in which the active material (2, 7) is coated and an uncoated portion in which the active material (2, 7) is not coated are provided on each surface of the collector (3, 8); in one or both of the positive electrode and the negative electrode, a boundary portion between the coated portion and the uncoated portion on a front surface of the collector (3, 8) is positioned planarly away from a boundary portion between the coated portion and the uncoated portion on a rear surface of the collector (3, 8), the secondary battery further comprising an insulating member which covers the boundary portion (4a, 4b) between the coated portion and the uncoated portion, and wherein when seen planarly, a distance between an end of the coated portion side of the insulating member located on the front or rear surface of the collector (3, 8), and the boundary portion (4a, 4b) between the coated portion and the uncoated portion on the other front or rear surface of the collector (3, 8), is larger by five times or more than an average thickness of the insulating member.