Lead Acid battery

A lead storage battery enabling the user to confirm the joined state of a cover and an upper cover by both the joined state of the projecting part of a second exhaust hole peripheral edge and the joined part of the upper cover and the joined state of the projecting part of the cover and the joined part of the upper cover. The lead storage battery comprises a battery case having at least one cell chamber and the cover (1) for covering the upper opening of the battery case. The annular projecting part (4C) projecting upward is formed on the inner side of a recess (4) formed in the upper surface of the cover (1). Exhaust holes (4D) for exhausting the gas from the cell chamber are formed in a bottom wall on the inner side of the projecting part. A guide passage for guiding the gas from the exhaust holes (4D) to the outside is formed by joining the projecting part (4C) and the connection part formed on the upper cover to each other. Groove parts (4M) formed between the projecting part and vertical walls are covered by the outer peripheral edge of the upper cover (5), and the guide passage is formed separately from the groove parts (4M).