Diamond films were synthesized by a microwave plasma-enhanced chemical vapor deposition method using H-2/CH4 gas mixtures. A Fluke PM6306 RCL Meter was used to study the dielectric properties of the diamond films deposited. The dielectric dispersion measurement yielded the real and imaginary parts of impedance of diamond films in the form of a depressed semicircle in a complex plane. A Cole-Cole plot was observed at frequencies from 50 Hz to 1 MHz. The result was found to fit the theoretical resistor-capacitor parallel circuit model. The structure and quality of diamond films were analyzed by scanning electron microscopy, X-ray diffraction and Raman spectroscopy.