Electron transport properties of nanostructured Pb thin film, consisting of grains, have been studied. Nanostructured thin films were fabricated on a substrate held at low temperature and their thicknesses were less than 10nm. While temperature of the film increased from 1.3 K to room temperature, the change in normal state sheet resistance has been measured. As the annealing temperature varies, the normal state sheet resistance shows a non-monotonic and irreversible change. Such behavior can be understood with the Pb grain growth due to annealing of the film.