This article is a study of electrostatic field homogeneity produced by system of wires cylindrically placed parallel to the axis. The study investigates the homogeneity in a chamber having 20 wires and compares results of different computation methods. The chamber can be a part of a charge particles beam deflecting system as good as it can be an electrostatic part of Wien velocity filter for electron/ion beams. Results of field homogeneity radius calculations are presented.