The thermal reordering process of a ball milled Fe-40Al at% alloy has been studied from magnetic and structural viewpoints. The reordering process has two distinct stages, which allows to separate the contribution of the grain and grain boundaries to the magnetization. The reordering temperature has been calculated from the derivative of the χDC. The reordering temperature decreases about 20 K when the applied magnetic field rises from 50 Oe to 3 kOe. Higher magnetic fields, up to 10 kOe, cause a small increase in the reordering temperature.