A magnetoresistive element includes a stack formed by sequentially stacking a first fixed layer in which a magnetization direction is fixed, a first nonmagnetic layer, a free layer in which a magnetization direction is changeable, a second nonmagnetic layer, and a second fixed layer in which a magnetization direction is fixed, a first circumferential wall provided on the second nonmagnetic layer in contact with a circumferential surface of the second fixed layer to surround the second fixed layer, and made of an insulator, and a second circumferential wall provided on the first nonmagnetic layer in contact with a circumferential surface of the free layer to surround the free layer, and made of an insulator.