PURPOSE: To improve a cycle life by containing a water soluble high molecule and rubber resin in a binding agent of holding hydrogen storage alloy powder in an electrode, so as to prevent the hydrogen storage alloy powder from coming off from the electrode.

CONSTITUTION: A binding agent containing a water soluble high molecule of methyl cellulose, polyvinyl alcohol, etc., in addition to rubber resin, is used. In the water soluble high molecule, since viscosity of slurry is increased, even without adding a large amount to the rubber system resin, viscosity of the active material slurry can be increased. Accordingly, a total amount of the binding agent is decreased, and charging density of a hydrogen storage alloy can be suppressed from decreasing. The slurry having sufficient fluidity is obtained, and it can be easily applied to an electrode supporter.