Electric double layer capacitor and battery

An electric double layer capacitor, comprising:

• at least one basic cell containing an electrolyte inside thereof, said basic cell may be laminated in its thickness direction to form a layered cell, including:
• a separator;
• a pair of polarized electrodes disposed so as to sandwich and make contact with said separator;
• a pair of collectors disposed so as to sandwich said polarized electrodes, each one of said pair of collectors making contact with the surface of one of said pair of polarized electrodes which opposes the surface making contact with said separator;
• and
• a gasket disposed between said pair of collectors so as to surround said pair of polarized electrodes;
• an electrode plate including an electrode body and a lead terminal extending from said electrode plate body, said electrode plate body being attached to the outer surface of each one of said collectors located at the outermost side in a laminated direction of said basic cell;
• an outer package which covers said basic cell and said electrode plate in a decompression state;
• and
• a sealing material having a higher gas barrier property than said collectors, said sealing material being disposed so as to seal an interface between each one of said collectors, which are located at the outermost side in a laminated direction of said basic cell, and said electrode plate body in said outer package.