A frame structure for an all-terrain vehicle includes upper main frame members and lower main frame members, each upper and lower main frame member extended in a longitudinal direction of the frame structure. The lower main frame members have forward and rearward portions mounted to the upper main frame members and central portions extended in a lateral direction of the frame structure outward of the upper main frame members. First sub-frame members are mounted to the forward and rearward portions of the lower main frame members. The first sub-frame members separate a component space defined by the frame structure into an upper component space and a lower component space. An electric motor is located in the lower component space, and a battery pack is located in the upper component space.