A
hydrogen storage
alloy includes a composition defined by the following formula (Ca1-XLX)(Li1-Y-ZMYNiZ)m, wherein the L denotes one or more elements selected from the group consisting of Na, K, Rb, Cs, Mg, Sr, Ba, Sc, Ti, Zr, Hf, V, Nb, Ta, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, the M denotes one or more elements selected from the group consisting of Cr, Mo, W, Mn, Fe, Ru, Co, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Si, Ge, Sn, Pb, Sb, Bi, and S, and the mole ratios X, Y, Z, and m respectively satisfy the following 0<X≦0.4, 0≦Y≦0.4, 0.1≦Z≦0.4, and 1.8≦m≦2.2.