To study the mechanism of a vacuum or gas breakdown, it is very important to research the prebreakdown phenomena including the generating charged particles (electrons, ions etc.). The difficulty of the experimental investigation of prebreakdown phenomena is to registrate a small number of charged particles. In the paper the problems connected with application of a plane two-electrode ionized chamber for tasks mentioned above are examined. The mathematical relationship between a charged particles concentration and their spatial distribution and the pulse current-voltage characteristic is found. It is shown that the chamber can be successfully used for the registration of charged particles arising at the prebreakdown stage.