A robot cleaner includes: a cleaner body; a suction unit provided at a front side of the cleaner body, and configured to suck dust-contained air; a cyclone unit provided at a rear upper side of the suction unit, the cyclone unit having a first suction opening and a second suction opening for sucking air, and the cyclone unit having a first cyclone and a second cyclone for passing air therethrough, the air having dust filtered therefrom by a centrifugal force; a first guiding member and a second guiding member upward extending from the suction unit toward the cyclone unit with an inclination angle, the first guiding member for connection between the suction unit and the first suction opening, the second guiding member for connection between the suction unit and the second suction opening; and a dust box communicated with a dust discharge opening provided at a front side of the cyclone unit so as to collect dust filtered by the cyclone unit, the dust box partially or wholly accommodated between the first and second guiding members.