In a structure of a disconnect plug of an electric vehicle, a plug bracket is raised from an inside of a battery unit to an inside of a bulge formed on a floor panel under rear seats for preventing a submarine motion of a passenger. In addition, a disconnect plug is detachably attached to a front face of a plug bracket, and an opening for accessing to the disconnect plug is formed on a front wall of the bulge. Further, a cover for covering the opening capable of being opened and closed is provided on a trim beneath a front face of a seat cushion of the rear seats.