Provided is an alloy powder for electrodes for nickel-metal hydride storage batteries which have high battery capacities, excellent service life characteristics and excellent high-temperature storage characteristics. A hydrogen storage alloy contained in this alloy powder for electrodes contains elements L, M, Ni, Co and E. The element L contains La as an essential component, and contains no Nd, or alternatively, in cases where Nd is contained therein, the ratio of Nd in the element L is less than 5% by mass. The ratio of La in the hydrogen storage alloy is 23% by mass or less. The element M is composed of Mg, Ca, Sr and/or Ba, and the molar ratio ([alpha]) of the element M in the total of the elements L and M satisfies 0.045 <= [alpha] <= 0.133. The molar ratio (x) of the element Ni relative to the total of the elements L and M satisfies 3.5 <= x <= 4.32; the molar ratio (y) of the element Co relative to the total of the elements L and M satisfies 0.13 <= y <= 0.5; and x, y and the molar ratio (z) of the element E relative to the total of the elements L and M satisfy 4.78 <= x + y + z < 5.03.