The preparation of a series of granular films (Fe20Ni80)(x)Ag100-x (5less than or equal toxless than or equal to95, x is the vol.%) of 200 nm thickness on mica substrates by electron beam evaporation technique is described. Structural and magnetic investigations are made by X-ray diffraction, magnetoresistive and ferromagnetic resonance techniques. The isotropic giant magnetoresistance effect as high as 6% in magnetic field of 8.2 kOe at room temperature and 13% at liquid nitrogen temperature is observed.