Power assist devices are broadening their range of application remarkably. According to that, these devices will expand the number of users, and will be casually used tools, which are sometimes shared in a group. In such a situation users must require a function of switching personal settings. Fortunately the power assist devices are able to observe difference of users' way of maneuvering, and it may enable to distinguish users. On these premises, this paper propose online personal identification through power assist operation behaviors. This paper examined the proposal on a setup with Skill Assist, a power assist device designed for car-production industries. The online identification method could identify the users at available short time in this experiment. By using the identification method, users can immediately obtain personalized maneuverability without performing any special authentication procedures.