The omni-directional drive device comprises a main wheel (2) comprising an endless annular member rotatable around a center of cross section perpendicular to a corresponding tangential line, electric motors (5R and 5L) for producing rotative forces around the rotation axis of the main wheel (2) and around the center of cross section perpendicular to a corresponding tangential line of the main wheel (2) and an arrangement (rotary members (4R and 4L) fitted with free rollers (3R and 3L)) for converting the rotational forces of the electric motors (5R and 5L) to the rotational forces around the rotation center of the main wheel (2) and around the center (C) of cross section perpendicular to a corresponding tangential line of the main wheel (2).