PURPOSE: To facilitate characteristic evaluation such as remaining life evaluation by equipping a conductor which is dipped into an alkaline aqueous solution and capable of being electrically connected with and cut from a negative electrode.

CONSTITUTION: A conductor 10, which is dipped as a test electrode into an alkaline electrolytic solution 11 and capable of electrically connected with and cut from a negative electrode 1, is further equipped in addition to a positive electrode 3 and the negative electrode 1. A very small electrode of hydrogen absorption alloy 12, which is capable of being electrically connected with and cut from a hydrogen absorption alloy electrode (a negative electrode) and insulated from the positive electrode, may be equipped as this conductor 10 in addition to said two positive and negative electrodes. When a surface area of the hydrogen absorption alloy electrode used as the conductor is made to be 0.05 to 0.2cm2, characteristic evaluation can be more facilitated.