This paper presents a rigorous analysis of electromagnetic scattering and transmission of metal gratings on a magnetized ferrite slab. The Fourier transform is used to represent the electric and magnetic fields in the spectral domain. The mode-matching technique is enforced to obtain two simultaneous equations for the modal coefficients of each slit region. Numerical results show that the metal gratings on the magnetized ferrite slab exhibit a steerable electromagnetic transmission property depending on the applied dc magnetic field and the saturation magnetization of ferrite material.