In this paper, partial discharges(PDs), lift off and breakdown voltage were measured when metal particles existed in a model GIS coated with epoxy resin on its bottom electrode, and the measured results were analyzed after comparing with the model DIS not coated. In order to presume the various fault case in GIS, we measured the experimental values with changing some experimental factors, such as the mixture ratio of SF$\_$6//N$_2$, the pressure of the gases, the kinds and diameter of the metal particles, and the coating thickness of the epoxy resin. As a result, the PDIV increased with the thickness of the epoxy resin, while the magnitude of PDs decreased at the same condition. The lift off voltages of steel alloy particles were higher than that of copper particles, and increased wit diameter of particles. Futhermore, the lift off voltages in the case of the electrode coated with epoxy resin were higher than that in the case of the uncoated one. In addition, the thicker the thickness of the epoxy resin was, the higher the breakdown voltage were. Thus, it was confirmed that the GIS coated with epoxy resin on its inner surface could be improved in insulation performance.