A cell having an excellent discharge load characteristic and an excellent low−temperature discharge characteristic. The cell has a coiled electrode element in which band−shaped positive and negative electrodes and a separator (23) impregnated with an electrolyte and interposed between them are coiled. The separator (23) includes a porous film (23a) such that the mean pore diameter is 0.15 µm or less, and the mean ratio of the largest diameter (D<sb>L</sb>) of the pores to the shortest diameter (D<sb>S</sb>) ranges from 0.4 to 1.0. As a result the pores (23b) are prevented from being plugged. The electrolyte permeability, ionic permeability, and electrolyte retainability of the separator (23) are improved. Consequently, the cell can have excellent discharge load characteristic and low−temperature discharge characteristic.
