It is possible to generate a resonance mode such that a dielectric resonator (20) can be resonated and an electric field vector leaking out from the resonator (20) exists by arranging antennas (22a and 22b) for the resonator (20). When a sample (22) has dielectric anisotropy, the resonance frequency of the resonator (20) varies when the sample (25) or resonator (20) is rotated. The dielectric anisotropy of the sample (25) is found from the variance of the resonance frequency. Thus the dielectric anisotropy of not only a sheet-like sample, but also such a sample as a three-dimensional molded sample can be measured.