To obtain porous alumina films, the precursor sol was prepared by hydrolysis of Al isopropoxide and then mixing with poly(ethylene glycol) (PEG). The porous alumina films were fabricated by dip-coating technique on glass substrates and heating at 500 °C. The film was composed of nano sized particles (30-50 nm). The maximum thickness of the film prepared by one-run dip-coating was ca. 1000 nm. The film had humidity-sensitive electrical resistance at room temperature.