We have designed and manufactured a flanged double ridged waveguide as a sample holder for measuring the electromagnetic shielding effectiveness of planar material in broadband frequency ranges up to 10 GHz. The newly proposed sample holder in this paper is with the tapered section for broadband impedance matching with the 50Ω coaxial feeding section. And we compared the measurement result with the simulation results by using the commercial software tool. The designed Sample Holder is well agreed with the fabricated ones in consideration with the design specification of S11 < -20 dB at operational frequency range. Also, to verify the measuring apparatus, we have tried to measure and compared the SEs of commercial shielding material made of NiC 100% by proposed sample holder and ASTM D4935 holder.