Abstract: A room air cleaner for use in automobiles is disclosed. The room air cleaner comprises: a housing and a cover which form a box-like body, inlet and outlet openings formed in opposite sides of the box-like body, and a discharge device, a filter, and a motor-mounted fan which are arranged in this order in said box-like body in a substantially horizontal direction starting from the side in which the inlet openings are formed. Thus, the room air cleaner achieves a low profile design of the product and thereby assures the driver of an enlarged rear view field, and is capable of operating more quietly without affecting its air suction capacity and dust collecting performance despite the low profile design.