A cleaner includes an impeller that is rotated by a motor, wherein the impeller includes a boss portion, a base portion, and a plurality of blades arranged radially on the base portion to generate a suction force. Each of the plurality of blades has a pressure surface, which is a front surface of each of the plurality of blades with respect to a rotational direction of the impeller, wherein the pressure surface is curved concavely toward the rotational direction.