NOVELTY - The separator (30) has a pair of mutually opposed separator units (31, 32), and an accommodating part (30a), which accommodates a positive electrode sheet (12). A junction part (30b) joins the separators by an edge side of the separators rather than the accommodating part. A penetration part (40a) penetrates the separators in the junction part. Resin-made fastening units (40) containing latching parts (40b, 40c) are provided in two ends of the penetration part, and protruded from an outer surface of the separator units. The fastening units are latched on the outer surface of the separator units.    USE - Electrode accommodation separator for an electrical storage apparatus e.g. secondary battery (all claimed) such as lithium ion secondary battery, which is utilized as a power supply of a motor of a hybrid vehicle and electric vehicle (EV). Can also be used for an electric double layer capacitor.    ADVANTAGE - The separator accommodates a positive electrode sheet in an inner side of a bag-like separator, so that number of stacking processes is reduced, and productivity of a battery is improved. The separator contains a contact surface that is in surface-contact with an outer surface of the separator, so that the separator is prevented from mutually deviating, or electrode is prevented from protruding out of the accommodating part, thus preventing the latching part protruded on the outer surface of the separator from becoming a burr and damaging the electrode positioned at the outer surface side of the separator.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) an electrical storage apparatus    (2) a method for manufacturing an electrode accommodation separator.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of an electrode accommodation separator.    Positive electrode sheet (12)    Electrode accommodation separator (30)    Accommodating part (30a)    Junction part (30b)    Mutually opposed separator units (31, 32)    Resin-made fastening units (40)    Penetration part (40a)    Latching parts (40b, 40c)