A melt of a hydrogen storage alloy having an arbitrary composition is cooled gradually at a cooling rate of 5.degree. C./min or less and solidified. Alternatively an alloy having an arbitrary composition, after heating to a temperature equal to or more than a melting point thereof, is cooled gradually at a cooling rate of 5.degree. C./min or less and solidified. Thereby a homogeneous alloy reduced in segregation, precipitates, or inclusions is obtained. The homogeneous alloy is excellent in the hydrogen storage amount, in the plateau property and in durability.