The damping mechanism of left-hand circularly polarized wave (L wave) near the electron cyclotron resonance (ECR) point, which has been considered not to be theoretically related to ECR, is investigated. The L wave and the right-hand circularly polarized wave (R wave) can be decomposed from the observed interferometric wave pattern, and it is found that not only the R wave but also the L wave is absorbed and damped in the ECR region. This damping of the L wave can be interpreted by the polarization reversal between the L and R waves. Furthermore, the polarization reversal from the L wave into the R wave is found to be enhanced in the lower electron temperature.