A robot cleaner configured to elastically deform a brush part using contact force between bristles and a floor and then restoring the brush part to vibrate the bristles, thereby improving cleaning performance. The robot cleaner includes a case that moves on a floor, a brush shaft mounted to the case such that the brush shaft rotates by driving force from a drive unit, an elastic member fixed to the brush shaft, the elastic member made of an elastic material, and a brush part fixed to the elastic member, the brush part having bristles, wherein the brush part generates generate vibration during deformation and restoration of the elastic member when external force is applied. The elastic member deforms due to contact force between the bristles and the floor and is then restored, and the brush part vibrates during deformation and restoration of the elastic member.