PROBLEM TO BE SOLVED: To provide a helical spring of a small spring constant, a connector, an electrode, and an electrometer.SOLUTION: An electrometer is provided with an electrode, an arithmetic unit, and a monitor. The electrode is provided with a helical spring. In the helical spring, a spring contant is 2.0 gf/mm or smaller until it is compressed to 50% or more in an axial direction.COPYRIGHT: (C)2014,JPO&INPIT【課題】ばね定数を小さくした蔓巻バネ、コネクタ、電極及び電位計を提供する。【解決手段】電位計は、電極と演算装置とモニタとを備え、前記電極は蔓巻バネを備え、前記蔓巻バネは軸方向に50%以上圧縮するまで、ばね定数が2.0gf/mm以下であることを特徴とする。【選択図】図2