, the structures described below are employed in the present invention. A spin valve thin-film magnetic device according to the present invention, comprises a free magnetic layer, a pair of nonmagnetic conductive layers formed on both sides of the free magnetic layer in the thickness direction thereof, a pair of fixed magnetic layers formed on the pair of nonconductive layers, a pair of antiferromagnetic layers formed on the pair of fixed magnetic layers, a pair of conductive layers imparting a sensing current to the free magnetic layer, the pair of nonmagnetic conductive layers, and the pair of fixed magnetic layers, and a pair of bias layers for aligning a magnetization direction of the free magnetic layer, wherein the free magnetic layer is a laminate composed of at least 0L ferromagnetic layers with a nonmagnetic interlayer provided therebetween, the L being an integer of 0 or more, in which magnetization directions of the ferromagnetic layers adjacent to each other are antiparallel to each other so that the entire free magnetic layer is in a ferrimagnetic state; one of the pair of 