The aim of this research is a physiological evaluation involving electroencephalographic analysis and subjective evaluation to identify differences in the usability of personal computer peripherals. As workload items, the speed of the mouse pointer is changed in three stages, and an electroencephalography is measured while the users performed a Trail Making Test. As a result, theta wave and the beta wave increased, and the alpha wave decreased when the movement speed of the mouse pointer was slow. It was suggested that brain function activity would change by the mental work load stress in usability of the personal computer peripherals.