According to one embodiment, a magnetoresistance effect element includes first and second shields, a stacked body and a hard bias unit. The stacked body includes first and second magnetic layers, an intermediate layer and a first Ru layer. A magnetization of the first magnetic layer is changeable. A magnetization of the second magnetic layer is changeable. The intermediate layer is nonmagnetic. The first Ru layer is provided between the first shield and the first magnetic layer. A thickness of the first Ru layer is not less than 1.5 nanometers and not more than 2.5 nanometers. The hard bias unit is provided between the first shield and the second shield. A first direction from the first shield toward the second shield intersects a second direction from the stacked body toward the hard bias unit.