A development of stair climbing mobile vehicle to be the base for stair climbing wheelchairs and/or inspection robots is greatly demanded. Several types of the vehicles using crawlers, wheels and legs have been proposed to perform such a stable stair climbing motion. However, conventional vehicles are limited by their mobility, safety, and mechanical size and weight. We propose a new stair climbing leg-wheel hybrid vehicle coined as“Zero Carrier”. The Zero Carrier composed of unified eight prismatic-joint legs, four of which attached active wheels and other four attached passive casters. Proposing Zero Carrier can be designed lightweight and powerful. It can also maintain high stability on stair climbing motion and perform slip-less turning motion. Design of driving mechanisms, sensors, and motion control of the Zero Carrier are then performed and demonstrated its motion by the mechanical model Zero Carrier I.