Provided is a robot cleaner including a main body including a suction portion disposed therein, a main wheel for moving the main body, wherein a vertical level of the main wheel varies in a vertical direction with respect to the main body, an auxiliary wheel disposed at a front portion or a rear portion of the main body, wherein a vertical level of the auxiliary wheel is fixed with respect to the main body, and a driving member assembly disposed in the main body, wherein the driving member assembly varies a vertical level of the main body from a floor face while rotating in forward and rearward directions of the main body, wherein the driving member assembly has different hitting radii when rotating forward and rearward.