A stacked battery comprising: a plate-like first electrode (41; 111); a plate-like second electrode (46; 112) having a polarity different from that of the first electrode (41; 111); and a separator, wherein the first and second electrodes (41, 46; 111, 112) each have a main portion (45, 50; 115, 116), and a connection portion (51, 52; 133, 134) extending outward from the main portion (45, 50; 115, 116) as viewed from above, and the main portions (45, 50; 115, 116) of the first and second electrodes (41, 46; 111, 112) are stacked in a thickness direction, the connection portion (51; 133) of the first electrode (41; 111) is fixed to a fixing member, a break portion that is to be broken when a shock is applied to the first and second electrodes (41, 46; 111, 112) is provided in the connection portion (51; 133) of the first electrode (41; 111) at a position outside the main portion (50; 116) of the second electrode (46; 112) as viewed from above when the first and second electrodes (41, 46; 111, 112) are placed on top of each other, and an outer shape of the main portion (50; 116) of the second electrode (46; 112) is larger than an outer shape of the main portion (45; 115) of the first electrode (41; 111) as viewed from above, characterized in that the separator is a bag-like member accommodating the first electrode, wherein the main portion of the first electrode is covered by the separator, and wherein a portion of the connecting portion of the first electrode close to the main portion is covered by the separator 44; and the main portion (50; 116) of the second electrode (46; 112) has the same size as that of the main portion (45; 115) of the first electrode (41; 111) once that is covered by the separator (44; 113). a plate-like first electrode (41; 111); a plate-like second electrode (46; 112) having a polarity different from that of the first electrode (41; 111); and a separator, wherein the first and second electrodes (41, 46; 111, 112) each have a main portion (45, 50; 115, 116), and a connection portion (51, 52; 133, 134) extending outward from the main portion (45, 50; 115, 116) as viewed from above, and the main portions (45, 50; 115, 116) of the first and second electrodes (41, 46; 111, 112) are stacked in a thickness direction, the connection portion (51; 133) of the first electrode (41; 111) is fixed to a fixing member, a break portion that is to be broken when a shock is applied to the first and second electrodes (41, 46; 111, 112) is provided in the connection portion (51; 133) of the first electrode (41; 111) at a position outside the main portion (50; 116) of the second electrode (46; 112) as viewed from above when the first and second electrodes (41, 46; 111, 112) are placed on top of each other, and an outer shape of the main portion (50; 116) of the second electrode (46; 112) is larger than an outer shape of the main portion (45; 115) of the first electrode (41; 111) as viewed from above, characterized in that the separator is a bag-like member accommodating the first electrode, wherein the main portion of the first electrode is covered by the separator, and wherein a portion of the connecting portion of the first electrode close to the main portion is covered by the separator 44; and the main portion (50; 116) of the second electrode (46; 112) has the same size as that of the main portion (45; 115) of the first electrode (41; 111) once that is covered by the separator (44; 113).