A robot cleaner comprising: a first housing including a controller and a driving wheel of which driving is controlled by the controller; a second housing disposed at one side of the first housing, the second housing having a brush module or mop module mounted thereto; a front bumper disposed at a front portion of the second housing, the front bumper configured to be movable to the inside of the second housing when the front bumper is in contact with an obstacle; at least one sensing means disposed at the inside of the front bumper to sense a movement of the front bumper to the inside of the second housing; side bumpers respectively disposed at left and right side portions of the second housing, the side bumpers each being configured to movable to the inside of the second housing when the side bumper is in contact with an obstacle; and a link member disposed at the inside of the side bumper to allow the side bumper and the front bumper to interlock with each other such that, when the side bumper is moved to the inside of the second housing, at least one portion of the front bumper is moved together with the side bumper to the inside of the second housing.