Welfare equipment is being developed for the projected barrier-free society. Stair climbers developed to help wheelchair users climb stairs include multileg, wheeled and crawler types. Stair climbers in practical use, however, may make traveling unstable depending on the stair or be expensive, indicating a need for improvement. This paper proposes a crawler stair climber, named ESCAL-F, that uses a small guide rail with a tooth belt installed at the side edge of stairs and a tooth belt for the crawler in which belts mesh to enable stair climbing. ESCAL-F realizes stable stair climbing with low cost. This paper focuses on design and tilt angle control of ESCAL-F.