An air cleaning unit includes a suction part into which contaminated air flows, a transfer body coupled with the suction part to support the suction part and to be raised up and down with the suction part; an elevation part connected to the transfer body and raising up and down the transfer body, a pivoting part connected to the suction part to pivot the suction part, and a filtering part communicating with the suction part and cleaning the contaminated air introduced into the suction part.