A lead-acid battery, including: a positive electrode plate; a negative electrode plate; an electrolyte solution; and a container having a cell chamber in which the positive electrode plate, the negative electrode plate and the electrolyte solution are accommodated. A concentration of Ba sulfate contained in a negative electrode material of the negative electrode plate is 1.0 mass % or more, and a Na concentration in the electrolyte solution is 0.04 mol/L or less.