We analyzed nanostructured Fe60Co40 alloy obtained by mechanical alloying using a planetary ball mill. The prepared powders were characterized using X-ray Diffraction (XRD), Laser particle-measurement, scanning electron microscopy (SEM), X band waveguide and cavity resonator associated with Network analyzer. Obtained results are discussed according to milling time. XRD patterns show after 12 h of milling the formation of a disordered solid solution having body-centerd cubic (bcc) structure. After 36 h milling, morphological studies indicated that the average crystallites size is around 13 nm and the particles average diameter is about 3.6 mu m. The microwave absorbing characteristic was enhanced between 0 and 54 h of milling (from -0.8 to -13.807 dB) with decreasing in the relative dielectric permittivity epsilon(r). (C) 2011 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.