A robot cleaner includes a main body which forms an external shape; two or more spin mops which rotate in a clockwise or counterclockwise direction when viewed from above and mop a floor with a damp cloth, and move the main body; and a cleaning module which is positioned in front of the spin mops and collects foreign substance existing on a cleaning target surface, wherein the cleaning module includes: a housing which is coupled to the main body and opened at a lower side; a dust container which forms a space for accommodating foreign substance and is positioned to be detachable in a lower side direction of the housing; and an agitator which is positioned inside the housing, and sends foreign substance existing on the cleaning target surface to the dust container by a rotation operation.