An MR element includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer disposed between the first and second ferromagnetic layers. The spacer layer includes a nonmagnetic metal layer, a first oxide semiconductor layer, and a second oxide semiconductor layer that are stacked in this order. The nonmagnetic metal layer is made of Cu, and has a thickness in the range of 0.3 to 1.5 nm. The first oxide semiconductor layer is made of a Ga oxide semiconductor, and has a thickness in the range of 0.5 to 2.0 nm. The second oxide semiconductor layer is made of a Zn oxide semiconductor, and has a thickness in the range of 0.1 to 1.0 nm.