In this investigation, the influences of cancer illness and related treatments on the mechanical specifications of rat healthy and cancerous (C6) brain cell were studied using nanoindentation by AFM. Chemotherapy as the first treatment was done by Cisplatin anti-cancer drug. The ideal concentration of Cisplatin was found by MTT assessment and supposing IC50 cell viability concentration for 24- and 48-h cultures. The results showed that Young’s modulus of healthy cell was decreased due to cancer and reached from 17.79 kPa to 2.446 kPa (0.139 times). By chemo treatment the Young’s modulus increases from 2.446 kPa to 3.482 kPa (1.423 times) and 38.38 kPa (15.691 times) for 24 and 48-h culture times. The second treatment was plasma treatment and was done for 30 and 60 s for 24 and 48-h culture times. The outcomes showed that applying the plasma treatment raises rapidly the cell rigidity for 48-h culture time. The results displayed that the width of rat healthy brain cell was larger than C6 (1.744 times). In the next section, theoretical and experimental methods were used to obtain the resonant frequencies and amplitude of the frequency response function of the AFM beam’s motion by supposing cells as specimens. The outcomes displayed that rising the specimens’ rigidity increases the resonant frequency. As the result, the resonant frequency of treated cells is bigger than untreated cell. Finally, the FEM and experimental results were evaluated. The comparison displays good agreement.