At hospitals, invasive medical techniques such as insertion of a central venous catheter are basic and common techniques for medical doctors. Since invasive techniques have impact on patient's body, standardization for quality assurance through prevention of any problems is important. In activities of standardization, not only preparation of operating procedure but also observation of process with operating procedure are required. In this paper, “observation of processes” is defined as an action to follow processes with operating procedures accurately. The purpose of this study is to develop a practical method for observation of processes with operation procedures and demonstrate efficiency of observation for invasive medical techniques. In this paper, we develop a method to observe processes using checklists in invasive medical techniques. In this method, processes are observed practically through implementation of checklists in daily operation of invasive medical techniques. In a verification for central venous catheter insertion process in hospital A, higher rate of observation have been achieved and improved outcomes of process performance have implied.