A distance H from a standard point O to one surface of a bottom plate of a terminal holding section 31 is set so that with respect to a direct wave that is output from one of a measurement antenna 25 and a wireless terminal that is a measurement target and is directly input to the other one thereof, a reflectivity of a reflection wave that is output from the one thereof, is reflected on one surface 32a of the bottom plate of the terminal holding section 31, and is input to the other one thereof is equal to or smaller than an incidence angle (for example, 80° or 70°) for assigning a predetermined allowable limit in view of a characteristic of incidence angle-to-reflectivity determined by a specific dielectric constant of the terminal holding section 31, to thereby reduce an influence of the reflection wave on measurement.