An electrode plate is configured by applying an active material onto a base member formed of a punching steel plate, the electrode plate being wound via a separator together with an electrode plate, which has a different polarity, and having an outermost peripheral portion positioned at the outermost periphery of an electrode assembly. The rate of hole area of the base member at a different electrode overlapping portion, which radially inwardly overlaps on a winding terminal end of the electrode plate having the different polarity, is smaller than that of the base member at the outermost peripheral portion.