To provide a four-wheel vehicle with prime mover having a driver's cab which can accommodate only one person widthwise and formed in a state unified with a chassis integrated with a protection structure of a driver, and a means for balancing a vehicle by simultaneous inclining of the chassis and two front wheels on a ground surface and/or in a curve which are inclined in relation to the horizon.

A four-wheel type vehicle 1 with a prime mover includes an inclination blocking means automatically intervening in stopping and at low speed. The vehicle includes a means for limiting the inclination to such a maximum value that, when stopped, the vehicle does not fall down. The vehicle is small in width, which enables travel in narrow places, and even with a small vehicle body width, the vehicle can remain stable in all of stopping, low speed traveling, high speed traveling, traveling in a curve and traveling within steps.