<p>Gas insulation switchgears are widely used in power grid, but it should be noted that these devices are expensive equipment that will impose a lot of costs on the energy network if they are not continuously monitored. The compact structure of these equipment has made it difficult for engineers to detect faults in them. The presence of free particles in gas enclosure is one of the possible defects in GIS, which reduces the gas insulation properties. These particles are often metallic and cause non-uniform distribution of the electric field governing the gas insulation space. The electric field increasing in an area can led to gas ionization in that area and increase the probability of partial discharge and insulation failure. In this article, a wire-shaped free particle is considered in different locations and angles in gas space, and using the ANN model, the effect of the location and angle of the particle on the non-uniformity of the electric field has been investigated. The obtained results show that both the location and the angle of free particle placement are effective on the non-uniformity of the electric field, but the effect of the particle location on the electric field disturbance is greater.</p>