In a method for manufacturing a magneto-resistance effect element having a pinned magnetic layer of which a magnetization is fixed substantially in one direction, a free magnetization layer of which a magnetization is rotated in accordance with an external magnetic field and a spacer layer, which is located between the fixed magnetization layer and the free magnetization layer, with an insulating layer and a metallic layer penetrating through the insulating layer, the spacer layer is formed by forming a first metallic layer; forming, on the first metallic layer, a second metallic layer to be converted into a portion of the insulating layer; performing a first conversion treatment so as to convert the second metallic layer into the portion of said insulating layer and to form a portion of the metallic layer penetrating through the insulating layer; forming, on the insulating layer and the metallic layer formed through the first conversion treatment, a third metallic layer to be converted into the other portion of the insulating layer; and performing a second conversion treatment so as to convert the third metallic layer into the other portion of the insulating and to form the other portion of the metallic layer penetrating through the insulating layer.