To advance new soft magnetic materials of an FeGaSi alloy into the commercial world, improvements on various properties were designed by introducing additive elements without sacrificing its high saturation magnetic induction. The detailed studies on the diversified properties, such as saturation magnetic induction, film internal stress, wear resistivity, and so on, were performed. High‐frequency permeability of the laminated structure film was also investigated. As a result, the Ru‐added FeRuGaSi alloy films, whose typical compositions are Fe72Ru4Ga7Si17and Fe68Ru8Ga7Si17(at. %), prove to be excellent soft magnetic materials especially appropriate for the magnetic recording/playback head core use.