Abstract
The space potential in plasma is one of the fundamental quantity which should be determined in the diagnostics. The potential of a probe immersed in the plasma is determined on the basis of the space potential. Therefore, the determination of the space potential has been discussed long time since the method of D.C. probe was established. However, it has remained with much ambiguity for a precise discussion. In this paper, the problem of the determination of the space potential is studied from some different stand points. It is conclusively described that the space potential can be determined within the error of some millivolts.
