To detect more accurately a change of an electrostatic field on the ground itself or in a space extremely near the ground; to analyze electrostatic field measured data of the ground on many spots; and to utilize it in real time to the utmost.
This electrostatic field measuring device 1 for measuring the electrostatic field on the ground J is characterized by including a metal spherical sensor 2 arranged with its lower end surface in contact with the ground surface or positioned near the ground surface, a cover body 4 having an electrifiable material for covering a peripheral space of the spherical sensor, and a detection part 10 for detecting a field change around the spherical sensor as a charge density difference caused by electrostatic induction.
ASAHARA YUTAKA
Mitsuo Tanaka
Hiroshi Kano