We demonstrated that the total reflection spectroscopy with the Si container attached on the prism was proved to be a powerful investigative technique. In addition, a new theory was induced to calculate the dielectric responses of several living glial-like cells based on the combination of the single-interface and double-interface ATR model. For the double interface ATR model, the sample was composed of the cell monolayer and the culture medium. For the single-interface ATR model, the sample was composed of the cell monolayer and the air medium after removing all the culture medium. The results showed the cell structure could impact on the dielectric responses in THz region significantly. Furthermore, these promising results suggest that the new method has great potential for the cancer detection in biomedical field.