The surface morphology of W-light polymerized monolayer Langmuir-Blodgett films of 10-12 pentacosadyinoic acid (12-8 diacetylene) deposited on flat gold substrates was imaged by atomic force microscopy. Current-voltage characteristics of the monolayer film was measured by using the tip of a scanning tunneling microscope at individual points on the film surface and compared to the ones measured on the bare gold substrate. The measured current-voltage characteristics are correlated and discussed with the expectation of the Au Fermi level of the substrate, Pt/Ir Fermi level of the tip and the higher occupied molecular orbital/lower unoccupied molecular orbital energy levels of the polydiacetylene molecule.