A method of manufacturing a wound electrode body by holding a first separator sheet between a pair of electrode sheets formed of a negative sheet and a positive sheet, laminating a second separator sheet in an outside of the pair of electrode sheets, and winding the pair of electrode sheets and the first and second separator sheets onto an outer circumferential surface of a winding core is provided. Before at least one electrode sheet of the pair of electrode sheets is attached to the winding core, a first fold line extended in a longitudinal direction of the one electrode sheet is formed in a leading part of the one electrode sheet.