The robotic cleaner includes a cleaner body that is movable and a suction unit that is movable relative to the cleaner body in a vertical direction. The suction unit includes an inlet for sucking impurities from the surface to be cleaned, and at least one support unit for spacing the inlet and the surface to be cleaned. With the configuration, the foreign substance suction efficiency from the surface to be cleaned may be improved, and a constant gap between the suction portion and the surface to be cleaned may be maintained.