Abstract: To provide a spherical roller which is capable of fully rotating when moving on a rough road surface with a small contact area and which produces no obstacle to the movement in other portions. The present invention comprises a spherical roller in a globular form, a housing on the undersurface of which an opening in a circular form is provided in such a way that the spherical roller is projected in a horizontal down direction, a support roller having rotatable contact with an upper side portion of the spherical roller within the housing, and a drive roller which is arranged in the housing and driven by a drive motor to rotate the spherical roller in a direction at an angle of 90 degrees different from the direction in which the support roller rotates from immediately above for friction drive, thereby driving the spherical roller to move the housing.