An automobile cell is provided with an electric power generating element composed of a positive electrode having a positive electrode active substance layer, a negative electrode having a negative electrode active substance layer and a separator interposed between the electrodes, a cell outer sheath made of a laminate film compositely composed of polymer and metal, a positive electrode terminal lead electrically conductive with the positive electrode and extending to an outside of the cell outer sheath, and a negative electrode terminal lead electrically conductive with the negative electrode and extending to the outside of the cell outer sheath. The positive electrode and the negative electrode associated therewith via the separator defines a unit electrode, and the relationship between a thickness of the automobile cell and a sum of a thickness of the positive electrode active substance layer and a thickness of the negative electrode active substance layer of the unit electrodes, is defined such that a value obtained by dividing the former by the latter is equal to or less than 80.