The application of FINEMET-type materials with specific magnetic properties prepared by the crystallization of amorphous alloys is often limited by their brittleness. The structure of these materials consists of nanosized Fe-based grains surrounded by an amorphous phase. Then the final macroscopic mechanical properties are considerably influenced by the properties of this amorphous phase. Direct creep measurements during the crystallization of FINEMET alloys were performed and the creep properties of the residual amorphous phase formed during the nanocrystallization were described. It was shown that due to relatively high temperatures, the residual amorphous phase undergoes intensive structural relaxation resulting in the obvious embrittlement of these materials.