AIR CLEANER

PROBLEM TO BE SOLVED: To seal a filter insert smoothly and surely, and reduce an installing space. SOLUTION: In a filter insert 3, a gasket 17 side is formed as a surface perpendicular to an air leading direction, a back surface side is formed on an inclining surface 19. A housing 2 is provided with a vertical seal part 7 and an inclining guide part 15 for guiding the vertical surface and an inclining surface of the filter insert 3, an opening surface 11 is formed on an upper part of the housing 2 freely to insert and take out the filter insert 3, and a clip 13 for locking a closing part 23 arranged on an upper part of the filter insert 3 is arranged on the outside of the opening surface 11. The surface of rubber is coated with lubricant such as graphite coat, or low frictional treatment is carried out on the gasket 17 using a gasket material such as cork, so that the vertical seal part of the housing 2 is slid and push-pressed by the gasket 17 when the clip 13 is locked with the closing part of the filter inset 3, and then the housing 2 is sealed by the filter insert 3.