An electric storage device comprising: - a positive electrode system including a positive electrode having a current collector and a positive-electrode mixture layer, - a negative electrode system including a negative electrode (14, 15) having a current collector and a negative-electrode mixture layer (20, 22), - wherein the negative electrode system includes a first negative-electrode mixture layer and a second negative-electrode mixture layer, which are connected to each other and which include at least one different material or have different material composition ratios, - wherein the first negative-electrode mixture layer and the second negative-electrode mixture layer have different charge/discharge characteristics, - wherein the negative electrode system further includes a first negative electrode and a second negative electrode that sandwich the positive electrode between them, and - wherein through-holes are formed in the current collector of the positive electrode arranged between the first negative-electrode mixture layer of the first negative electrode and the second negative-electrode mixture layer of the second negative electrode, characterized in that: the first negative-electrode mixture layer contains one selected from the group consisting of a polyacene-based organic semiconductor which is a heat-treated material of an aromatic condensation polymer and has a polyacene skeletal structure in which a ratio H/C of a number of hydrogen atoms H to a number of carbon atoms C is 0.05 or more and 0.50 or less, a graphite, and a hard carbon, as a negative-electrode active material, and wherein the second negative-mixture layer contains one selected from the group consisting of two of the above three active materials other than the negative-electrode active material contained in the first negative-electrode mixture layer, as a negative-electrode active material. - a positive electrode system including a positive electrode having a current collector and a positive-electrode mixture layer, - a negative electrode system including a negative electrode (14, 15) having a current collector and a negative-electrode mixture layer (20, 22), - wherein the negative electrode system includes a first negative-electrode mixture layer and a second negative-electrode mixture layer, which are connected to each other and which include at least one different material or have different material composition ratios, - wherein the first negative-electrode mixture layer and the second negative-electrode mixture layer have different charge/discharge characteristics, - wherein the negative electrode system further includes a first negative electrode and a second negative electrode that sandwich the positive electrode between them, and - wherein through-holes are formed in the current collector of the positive electrode arranged between the first negative-electrode mixture layer of the first negative electrode and the second negative-electrode mixture layer of the second negative electrode, the first negative-electrode mixture layer contains one selected from the group consisting of a polyacene-based organic semiconductor which is a heat-treated material of an aromatic condensation polymer and has a polyacene skeletal structure in which a ratio H/C of a number of hydrogen atoms H to a number of carbon atoms C is 0.05 or more and 0.50 or less, a graphite, and a hard carbon, as a negative-electrode active material, and wherein the second negative-mixture layer contains one selected from the group consisting of two of the above three active materials other than the negative-electrode active material contained in the first negative-electrode mixture layer, as a negative-electrode active material.