Permittivity of about 1 µm thin films prepared from polymethylmetactrylate (PMMA) solution doped with 20 % of diphenyl sulfoxide was studied. Permittivity of the films was measured as a function of the temperature. The measurement of the dependence of polarization on electrical field was performed using a standard Sawyer-Tower circuit. The presence of the dopant increases the composite permittivity namely above the PMMA glass transition temperature. Hysteresis loops observed on the measured polarization vs. electrical field dependence indicate easier and more pronounced polarizability of the composite comparing to pristine PMMA.