NOVELTY - The assembly (10) has a pair of electrode terminals (40) including an electricity collector terminal being electrically conductive to an electrode, a rod-shaped penetrator penetrating through a lid, a flange extending in disk shape about the penetrator, and an external terminal to be connected to an outside connector. The collector terminal, the penetrator, the flange and the external terminal are made from a plastic rod. An engager is operated cooperatively with the flange to hold the lid between the engager and the flange for fixing the lid by the flange and the engager.    USE - Lid assembly for battery i.e. square-shaped sealed lithium-ion secondary battery, used in an electric vehicle or portable electronic appliance.    ADVANTAGE - The assembly utilizes reduced number of components. The reliability and electric conductivity of the electrode terminals can be improved while improving yield or productivity of material. The assembly includes a snap ring that makes the engager to be engaged with an engagement groove that is impressed into the penetrator of the electrode terminal, thus fixing the electrode terminal to the lid in a convenient manner. The snap ring together with the flange firmly holds the lid between the snap ring and the flange, thus generating stable rigidity for securing the electrode terminals to the lid while simplifying construction for fixing the lid, and hence enabling the engager or snap ring and the penetrator with the engagement groove impressed to fluctuate less in assembly accuracy and fixing the electrode terminals to the lid in an accurate manner. The lid assembly comprises a seal that intervenes between the flange and the lid, so that the lid assembly is upgraded in the function of sealing.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a lid assembly.    Lid assembly (10)    Lid (30)    Electrode terminals (40)    Bent section (43a)    Rod-shaped upright section (43b)    Seal (50)    Rubber seal (52)    Resin gasket (54)