We have developed an experimental apparatus and confirmed that vibration can be suppressed by applying a caster angle to a caster during high-speed traveling. Public transportation services are declining, especially in highly mountainous areas, causing a reduction in the range of activities and the quality of life. Therefore, micro-mobility is attracting attention. Micro-mobility refers to vehicles that are small and can seat about two people. By applying active-casters to these vehicles, it is expected to improve the range of activities by enabling omnidirectional movement and intuitive operation on narrow roads. The active-caster is effective in terms of durability and vibration reduction because it can move in all directions using normal tires. However, there is concern that the steering axis may oscillate from side to side at short intervals when moving at high speeds with normal tires. Therefore, in this study, we developed an experimental apparatus to verify traveling of the active-caster at high-speed. However, in this case, traveling verification was conducted on a passive caster as a preliminary experiment. As a result, vibration of the steering axis of the caster was confirmed, and it was also confirmed that the caster angle suppressed oscillate at high speed.