To estimate the dielectric permittivity in high frequency, a method measuring the field strength of scattered waves re-radiated from the dielectric sample placed in a applied well-known field was proposed. This method can easily estimate the dielectric permittivity without contact in small sample size compared to the wavelength. The permittivity of the pure water which radiates the relatively larger scattered waves is estimated in order to certify the measurement principle. The sample is enclosed by spherical rubber in diameter of 80 mm and the scattered field is discriminated from applied field by absorbers arranged between transmitting and receiving antennas. For the samples which have the relatively small dielectric permittivity, the scheme which modulates the strength of scattered waves by mechanical vibrations to discriminate the scattered field superposed with the applied electric field and the coherent approach in receiving process, is introduced. In this case, the calibration technique using the calibrator whose volume, shape and dielectric permittivity are well-known is available practically. At the field frequency, 1 GHz, the dielectric permittivity of spherical Teflon of 20-mm diameter can be estimated with the error of 2 percents when the measuring system is calibrated by the Alumina calibrator of the same diameter.%誘電体の高周波誘電率を推定するために，既知の高周波放射電界中に置いた誘電体試料から再放射される散乱波の電界強度を計測する方法を提案している．この方法は，誘電率を非接触かつ簡便に推定でき，試料サイズが信号波長に対して小さくて良いという特徴を有する．散乱波強度が比較的大きな純水を直径80mmの球形容器に封入した試料に関して，送受信アンテナ間に設置した電波吸収体により印加電界から散乱波電界を分離測定することで直接的な誘電率推定を検証した．相対的に誘電率の小さな試料に関しては，その散乱波強度を機械振動により変調することにより，印加電界と重畳して受信される散乱波を同期検波により分離する手法を用いた．この際，誘電率と形状・体積が既知のキャリプレータによる推定値を基準とした置換法の導入が実用的な手段である．印加電界周波数1GHzにおいて，直径20mmのアルミナ球により校正した測定系において，同直径のテフロン球の誘電率を誤差2％で推定できた．
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