The aim of this paper is to establish the optimum fabrication condition of specimens, using the Vapor Deposition Polymerization Method(VDPM), which is one of modesto prepare functional organic thin films using a dry process, and to develop a thin film type humidity sensor which has good humidity sensitive characteristics. The inner part of the film became denser and roughness of the film surface eased as curing temperature increased so that thickness of the film could be made uniform. This also shows the appropriate curing temperature was $250^{circ}C$. The basic structure of the humidity sensor is a parallel capacitor which consists of three layers of Aluminum/Polyimide/Aluminum. The result of SEM and AFM measurement shows that the thickness of PI thin films decreased and the refraction increased as curing temperature increased, which indicates that a capacitance-type humidity sensor utilizing polyimide thin film is fabricated on a glass substrate. The characteristics of fabricated samples were measured under various conditions, and the samples had linear characteristics in the range of 20-80 %RH, independent of temperature change, and low hysteresis characteristic.