Ultra thin film of Ag deposited using magnetron sputtering werefound to be porous in nature and its porosity reduces with the increase inthickness. We present here some results on formation of periodic patternhaving nano-size wire like structure on this porous film of Ag deposited onSi(001) substrate using the tip of the Atomic Force Microscope (AFM)cantilever. This pattern is induced by the interplay of tip-surfaceinteraction and the adhesive force between the Ag particle and thesubstrate. The periodicity and growth direction of the wire like structureis mostly determined by the thickness of the deposited film. With theincrease in thickness of the Ag film the growth direction of these wireschanges from 45° angle to 90° angleto the scan direction. We have also observed that if the thickness of thedeposited film is below a critical thickness then a carpet like growthoccurs and beyond this critical thickness the film undergoes moundformation. The mound size increases as the thickness of the film increases.The onset of the mound growth inhibits the formation of the pattern inducedby the tip of the AFM cantilever. This process of the pattern formation ofthe ultrathin films may have a wide application in the field ofnanotechnology.