Saturation magnetization and thermomagnetic curves were determined on FINEMET-type glassy precursors after different heat treatments below the nanocrystallization temperature. Saturation magnetization ( M s) shows a maximum at the early stage of nanocrystallization, then it drops to below the M s characteristic for the as-quenched state. Curie temperature of the amorphous phase ( T c am) increases continuously due to structural relaxation up to the beginning of nanocrystallization. The results are interpreted on the basis of irreversible structural relaxation as well as Si redistribution between the Fe(Si) nanograins and the intergranular amorphous shell.