The electric power is indispensable and its stable supply is always expected. A stable supply needs the real-time observation of load conditions by measurement of power factor. In addition, the various faults have been caused from the harmonic voltage and current. In the authors' laboratory, the sensor, which simultaneously measures both the waveforms of the voltage and current without contacting the conductors in the three-phase power distribution system directly, has been designed and implemented. Using the sensor, we will observe the power factor and harmonics from the measured waveforms of voltage and current in power distribution line. However, the experimental sensor was designed to be applied to the 6.6 kV power distribution system in the dielectric strength. The authors will propose the sensor for the 22 kV power distribution system and investigate the output characteristics of this new sensor from numerical results based on the finite element method.