A cleaner includes a case having an opening formed in a lower side. The cleaner also includes a brush assembly disposed inside the case. The brush assembly includes a horizontally disposed brush bar and a brush coupled to the brush bar. The cleaner includes a suction port for suctioning dust collected by the brush assembly. The cleaner also includes a motor that provides power to the brush assembly. Further, the cleaner includes an operation assembly, connecting the motor and the brush assembly, and converting a rotational movement of the motor into a translational motion of the brush assembly. The operation assembly includes a rotating member coupled to a shaft of the motor, a link connected to the rotating member, a connecting member connecting the brush bar and the link, and a guide rail for guiding the connecting member in a longitudinal direction.