PURPOSE: To improve stability and riding comfortablemess by preparing at least one wheel as a barrel type which has an arc to the shaft direction, and specifying the radius of corvature of the arc, and a relation between the radius of curvature of the arc and the wheel width.

CONSTITUTION: A front wheel 3 connected to a steering unit 2, and a rear wheel 6 connected to a driving motor 4 which is driven by a battery 5 are set in a roofed body 1 of a two-wheeled vehicle. In this case, at least one wheel among the front wheel 3 and the rear wheel 6, for instance, rear wheel is formed in a barrel form which has an arc to the shaft direction, and is made by putting a tire 8 of hard rubber made, around a wheel 9 made of a light alloy etc. The radius of corvature R of an arc of the barrel type wheel is made bigger than the height of the center of gravity of the wheel body 1, and the relation between the radius of curvature R of the arc and the wheel width W is set in the scope of R/W=0.85W2.2. Therefore, running stability as well as the restoring force at an inclined position of the body 1 can be improved.