In pure pentacene film and iodine doped pentacene film, X-ray and electric conductivity measurements were performed. It was found from X-ray diffraction data that the iodine doped pentacene possess the stage-2 structure in addition to the stage-1 structure. The c axis lattice constant of the stage-2 structure, which is the length of the interval between the layers, was determined to be 33.2 Å. Moreover, electric conductivity was measured in pentacene doped with iodine at the various doping temperaturesTd. This result was compared with the results obtained from X-ray diffraction data.