To provide a checking vehicle for roller coaster for checking a rail and a rail supporting structure while self-traveling in all the direction at 360° on vertical and horizontal planes while using an internal combustion engine on the marker as a motive force.

The wagon of a checking vehicle 1 is arranged with an outer cage 2l, the outer cage 21 is moved like a pendulum, the supporting point axis of that pendulum is also used as driving axes 9a and 9b, further, an inner cage 15 is arranged inside the outer cage 21, that inner cage 15 is also moved like a pendulum vertically to the pendulum swinging direction of the outer cage 21, and the supporting point axis of that pendulum is also used as driving axes 8a and 9b. Thus, even in the case of omni-azimuth rail traveling, internal combustion engines 16a and 16b installed in the inner cage 15 can be self-traveled while keeping normal posture at all the time and a rail 2 and the rail supporting structure 3 can be checked.