Abstract: There is provided a vanadium solid-salt battery including: a positive electrode and a negative electrode each containing vanadium of which oxidation number in an initial state is trivalent or tetravalent; and a separator which separates the positive electrode from the negative electrode and which allows hydrogen ions to pass therethrough, wherein maximum valence change in initial charging of the vanadium contained in one of the positive and negative electrodes is divalent, and maximum valence change in the initial charging of the vanadium contained in the other of the positive and negative electrodes is monovalent; and mole number of the vanadium of which maximum valence change is monovalent is not less than 1.5 times mole number of the vanadium of which maximum valence change is divalent.