An air cleaner that is capable of efficiently and effectively purifying and humidifying air. An air flow passage from air filters (4, 5) to a blower (8) is branched to first and second air flow passages (31, 32), and then these air flow passages join. A humidifying filter (14) is disposed in the first air flow passage (31), and a movable plate (35) for opening and closing the humidifying filter is disposed in the second air flow passage (32). The air cleaner comprises a control part (40) for controlling the opening and closing operation of the movable plate (35) and the rotating operation of the blower (8). A recess containing the air filters (4, 5) is formed in the front of the body (2) of the air cleaner. An air flow passage extending from under the recess to the back of the recess and bent upward is horizontally partitioned into upper and lower parts by a partition wall (27) to form the first air flow passage (31) and the second flow passage (32) in this order from the bottom. The movable plate (35) is a flat plate rotated around a pivotal axis (36) formed along one lateral side.