A magnetic field detecting element comprises: a stack which includes first, second and third magnetic layers whose magnetization directions change in accordance with an external magnetic field, the second magnetic layer being positioned between the first magnetic layer and the third magnetic layer, a first non-magnetic intermediate layer which is sandwiched between the first magnetic layer and the second magnetic layer, the first non-magnetic intermediate layer producing a magnetoresistance effect between the first magnetic layer and the second magnetic layer, and a second non-magnetic intermediate layer which is sandwiched between the second magnetic layer and the third magnetic layer, the second non-magnetic intermediate layer allowing the second magnetic layer and the third magnetic layer to be exchange-coupled such that magnetization directions thereof are anti-parallel to each other under no magnetic field, the stack being adapted such that sense current flows in a direction that is perpendicular to a film surface thereof; and a bias magnetic layer which is provided on a side of the stack, the side being opposite to an air bearing surface of the stack, the bias magnetic layer applying a bias magnetic field to the stack in a direction that is perpendicular to the air bearing surface.