The "mist irrigation system" (MIS) is a new and effective method at drilling in spinal surgery. In this report, MIS is introduced with subsequent demonstration that visibility at drilling is better with MIS because of the reduction of smoke, blood and irrigation water. Additionally using a 5 mm-thick acryl plate, the time for perforation by drilling and temperature after drilling with MIS, drip-irrigation (DI) or no irrigation, were measured respectivily. Using the acryl plate significantly reduced drilling time and high temperature after perforation in the group without irrigation were recognized, compared to cases in the groups with MIS or DI. The results might indicate that the high temperature of the drill might melt the acryl plate immediately. As a conclusion, MIS might help surgeons to drill in the deep and narrow operative field. Additionally it might help to reduce the risks of heat injury to neuronal tissue by cooling efficiently.