A magnetoresistive element is disclosed that includes a magnetoresistive film; a cap film configured to cover the magnetoresistive film and include a three-layer structure in at least a part thereof, the three-layer structure being formed of a third protection layer, a second protection layer, and a first protection layer in order from the magnetoresistive film side; and upper and lower terminals for applying a sense current perpendicularly to the surface of the magnetoresistive film. The magnetoresistive film includes a first magnetic layer whose direction of magnetization is changed by an external magnetic field, a second magnetic layer whose direction of magnetization is fixed with respect to the external magnetic field, and a nonmagnetic layer magnetically separating the first magnetic layer and the second magnetic layer.