The types of artifacts that are observed in intraoperative neurophysiological monitoring (INM) is truly diverse. The removal of artifacts that interfere with the examination is essential. In addition, improving the quality of the examination by removing artifacts is a reflection of the competency of the examiner and is also the best way to ensure patient safety. However, if knowledge of the equipment or anesthesia in the operating room is insufficient due to lack of experience, artifacts cannot be removed even with a method appropriate to the situation. If artifacts are not separated and removed, the reading of the examination results in confusion in the operation process. This can be a fatal problem in neurosurgery that requires rapid and sophisticated procedures. In this paper, the causes of artifacts that occur during surgery are classified into electrical factors, non-electrical factors, and other factors, and a method and examination method for removing artifacts according to the specific situation is mentioned. Although the operating room environment is a very critical place to simultaneously consider various scenarios, we hope that a stable and optimal INM will play a role by knowing the types and causes of various artifacts and how to tackle them.