A magnetoresistance effect element of the present invention includes: a barrier layer; a reference layer formed on one surface of the barrier layer; a free layer formed on the other surface of the barrier layer; and a pinned layer placed on the opposite side of the reference layer from the barrier layer. The pinned layer includes a structure obtained by stacking Ni, Co, Pt, Co, Ru, Co, Pt, Co, and Ni layers in this order.