The influence of heating on the electrical and magnetic properties of Fe 75 Ni 2 B 13 Si 8 C 2 amorphous alloy is studied under non-isothermal as well as under isothermal conditions. According to thermal analysis the amorphous alloy was stable up to a temperature of about 500 • C when the process of multi-step structural transformations begins. According to the X-ray diffraction analysis, the primary crystallization starts by forming iron-silicon (Fe 3 Si, 70 wt%) as main phase and two minor phases, iron-boron (Fe 2 B, 10 wt%) and iron-boron-silicon (Fe 15 B 2 Si 3 , 20 wt%). With the increase of the temperature, the change of weight composition, as well as the ratio of present phases occurs, and at 650 • C it was confirmed the presence of only two stable phases, Fe 3 Si (74 wt%) and Fe 2 B (26 wt%). It was shown that the observed change of structure had significant influence on both the electric and magnetic properties of alloy. The electric resistivity in crystallized alloy is higher than the amorphous one, but the crystallized alloy possesses better magnetic susceptibility and retains the ferromagnetic properties in the whole investigated temperature range.