Abstract: A sealed lead-acid storage battery having a long trickle life, being excellent in the welded strength between the container cover and the top lid covering the part of the container cover where a vent valve is provided, and having a high reliability is disclosed. The battery comprises: a container for accommodating an electrode group, a container cover for closing an open end of the container by being bonded to the open end of the container with a resin adhesive, and a top lid for covering a part of the container cover where a vent valve is provided by being bonded to the container cover by means of ultrasonic welding, wherein the container is formed with a denatured polyphenylene ether resin containing a flaky inorganic substance of humidity non-transmitting property, whereas the container cover and the top lid are formed with acrylonitrile-butadiene-styrene resin containing no flaky inorganic substance of the humidity non-transmitting property.