Magnetic properties of sputtered multilayer Fe100-xY x/Si3N4 films (x=0-3.5 at. %) were studied. We developed heat resistant and corrosion resistant soft magnetic films having high saturation induction (Bs). The Fe97.7Y 2.3/Si3N4 film has a Bs value of 17.3 kG, a coercive force (Hc) of 0.9 Oe, permeability at 5 MHz (μ) of 2800 and magnetostriction (λs) of ∼-1×10-6 after being annealed at 600°C.