A wave absorber based on rubber sheet with circular lattice using metal mesh is proposed for improving ETC environment, and characteristics of the reflectivity and the shielding effect are evaluated analytically and experimentally. As a result, it is confirmed that the reflectivity of -13dB at the incident angle ranging from 5 to 45 degrees and the shielding effect of -25dB at the incident angle ranging from 0 to 30 degrees are obtained for circularly polarized wave used in ETC system. Therefore, realization of proposed wave absorber can be clarified.