A magnetic detecting device includes a first and a second magnetoresistive element, and a first and a second fixed resistor connected in series to the first and the second magnetoresistive element, respectively. The first and the second magnetoresistive element each include a pinned magnetic layer and a free magnetic layer with a nonmagnetic conductive layer in between. The first and the second magnetoresistive element have the same layer structure except that the nonmagnetic conductive layers have different thicknesses. The thicknesses of the nonmagnetic conductive layers are set so that a positive interlayer coupling magnetic field acts between the free magnetic layer and the pinned magnetic layer of the first magnetoresistive element and a negative interlayer coupling magnetic field acts between the free magnetic layer and the pinned magnetic layer of the second magnetoresistive element. The first and the second fixed resistor have the same layer structure.