The present invention provides a hydrogen absorbing alloy containing as a principal phase at least one phase selected from the group consisting of a second phase having a rhombohedral crystal structure and a first phase having a crystal structure of a hexagonal system excluding a phase having a CaCu₅ type structure, wherein a content of a phase having a crystal structure of AB₂ type is not higher than 10% by volume including 0% by volume and the hydrogen absorbing alloy has a composition represented by general formula (1) given below:

R_1-a-bMg_aT_bNi_Z-X-Y-M1_XM2_YMn.   (1)