This is a manually operated experimental demonstrator of ellipsometry. An input beam of random polarization is first transferred to a linearly polarized beam by passing through a polarizer, and is then transferred to an elliptically polarized beam by using a quarter-wave plate. As the beam is further incident on a sample film, the polarization status of the beam reflected from the film will be altered. Optical parameters such as the thickness and refractive index of the sample film can be calculated by analysis of the change in polarization. Through this system, students can gain a better understanding of the working principle of an ellipsometer and familiarize with the operation of the instrument.