Magnetic and magneto-optical properties of Fe/Si multilayered films prepared by electron beam evaporation have been studied. By X-ray diffraction, an artificial period is confirmed for the film with a period of more than 16A, and structures of both Fe and Si monolayers are confirmed to be amorphouslike. Polar Kerr rotations are very small in the short wavelength region, increase with increasing wavelength, and have maximum values at 700∼1000 nm. When Fe monolayer thickness is constant, the wavelength for maximum Kerr rotation angle shifts to a longer region with increasing Si monolayer thickness. The Kerr rotation angle and reflectivity calculated from optical constants of Fe and Si considering optical interference do not agree with experimental results. But assuming that an FeSi alloy layer exists at the Fe-Si interface, the agreement between the calculation and the experimental results is improved.