Conventional magnetization methods only measure the average magnetic properties over the whole sample. The information is insufficient to understand the local character. This paper presents the visualized magnetization process and its profiles in detail at the cross section of the FINEMET ribbon using advanced magnetooptical imaging technique. External magnetic fields were applied parallel to the surface of the ribbon. A magnetization curve was plotted by interpreting the profile of intensity of magnetooptical images. The profile indicates that the flux densities are higher at the cross section of the ribbons compared with those at the gaps between the ribbons. The flux lines mainly transmit inside the FINEMET ribbons though there are some stray fields between the ribbons.