Polymethylmethacrylate (PMMA)'s thermal and mechanical stability, high resistivity, and suitable dielectric constant make it an ideal candidate for the polymer thin film for the dielectric layer. PMMA thin films were fabricated on a glass substrate, using the spin coating process, at room temperature. The thermal-degradation temperature of PMMA was about 280 degrees C, and the glass transition temperature (Tg) was about 110 degrees C. To determine the effect of annealing, the coating films were annealed at 70-200 degrees C for 60m under argon atmosphere. The surfaces of the coating films were compact and uniform at all the annealing temperatures. The surface energies of the coating films were obtained by measuring the contact angles with deionized water and di-iodomethane. The coating films were found to have low surface energies. Up to below Tg, the dielectric constants of the coating films slightly increased owing to an increase of the total polarization arising from dipoles and trapped charge carriers. Above Tg, the coating films began to degrade; as such, their dielectric constants decreased. To ensure the reliability of the thermal endurance of the dielectric properties of the coating films, annealing was repeated three times, at 100 degrees C. The coating films then showed no degraded dielectric properties.